United States

2007 Schools Wikipedia Selection. Related subjects: Countries; North American Geography

United States of America
Flag of the United States Great Seal of the United States
Flag Great Seal
Motto: E Pluribus Unum ("Out Of Many, One") (traditional)
In God We Trust (1956 to date)
Anthem: The Star-Spangled Banner
Location of the United States
Capital Washington, D.C.
38°53′N 77°02′W
Largest city New York City
Official languages None at federal level
(English de facto)
Government Federal republic
 - President George Walker Bush (R)
 - Vice President Dick Cheney (R)
Independence from Great Britain 
 - Declared July 4, 1776 
 - Recognized September 3, 1783 
 - Total 9,631,420 km² ( 3rd1)
3,718,695 sq mi 
 - Water (%) 4.87
 - 2006 estimate 300,307,297 ( 3rd)
 - 2000 census 281,421,906
 - Density 31/km² ( 172nd)
80/sq mi
GDP ( PPP) 2006 estimate
 - Total $13.049 trillion ( 1st)
 - Per capita $43,555 ( 3rd)
GDP (nominal) 2005 estimate
 - Total $12.485 trillion ( 1st)
 - Per capita $42,000 ( 8th)
HDI  (2004) 0.948 (high) ( 8th)
Currency United States dollar ($) ( USD)
Time zone ( UTC-5 to -10)
 - Summer ( DST) ( UTC-4 to -10)
Internet TLD .us .gov .edu .mil .um
Calling code +1
1 Sometimes listed as 4th; the rank is disputed with China.

N. Dakota
S. Dakota

The United States of America, also known as the United States, the U.S., the U.S.A., the U.S. of A., The States and America, is a country in North America that extends from the Atlantic Ocean to the Pacific Ocean and shares land borders with Canada and Mexico. The United States is a federal republic, with its capital in Washington, D.C.

At over 3.7 million square miles (over 9.5 million km²), the U.S. (including its non-contiguous and overseas states and territories) is the third largest country by total area. It is the world's third most populous nation, with over 300 million people, as well as the world's most populous Christian-majority nation, with members representing all major denominations.

American military, economic, cultural, and political influence increased through the 19th and 20th centuries. With the collapse of the Soviet Union at the end of the Cold War, the nation emerged as the world's sole remaining superpower, and today, the United States plays a major role in world affairs.


The earliest known use of the name America is from 1507, when a globe and a large map created by the German cartographer Martin Waldseemüller in Saint-Dié-des-Vosges described the combined continents of the North and South Americas. Although the origin of the name is uncertain, the most widely held belief is that expressed in an accompanying book, Cosmographiae Introductio, which explains it as a feminized version of the Latin name of Italian explorer Amerigo Vespucci (Americus Vespucius); in Latin, the other continents' names were all feminine. Vespucci theorized, correctly, that Christopher Columbus, on reaching islands in the Caribbean Sea in 1492, had come not to India but to a " New World".

The Americas were also known as Columbia, after Columbus, prompting the name District of Columbia for the land set aside as the U.S. capital. Columbia remained a popular name for the United States until the early 20th century, when it fell into relative disuse; but it is still used poetically and appears in various names and titles. One female personification of the country is called Columbia; she is similar to Britannia. Columbus Day is a holiday in the U.S. and other countries in the Americas commemorating Columbus' October 1492 landing.

The term "united States of America" was first used officially in the Declaration of Independence, adopted on July 4, 1776. On November 15, 1777, the Second Continental Congress adopted the Articles of Confederation, the first of which stated "The Stile [sic] of this Confederacy shall be 'The United States of America.'" The name was originally proposed by Thomas Paine.

The adjectival and demonymic forms for the United States are American, although the use of this term has been disputed, as it can also refer to inhabitants of both North and South America.


A satellite composite image of the contiguous U.S.  Deciduous vegetation and grasslands prevail in the east, transitioning to prairies, boreal forests, and the Rocky Mountains in the west, and deserts in the southwest. In the northeast, the coasts of the Great Lakes and Atlantic seaboard host much of the country's population.
A satellite composite image of the contiguous U.S. Deciduous vegetation and grasslands prevail in the east, transitioning to prairies, boreal forests, and the Rocky Mountains in the west, and deserts in the southwest. In the northeast, the coasts of the Great Lakes and Atlantic seaboard host much of the country's population.
Mount Hood, a dormant volcano in the Pacific Northwest.
Mount Hood, a dormant volcano in the Pacific Northwest.

The United States is the world's third or fourth largest country by total area, and the second largest by land area alone, after Russia. Its contiguous portion is bounded by the North Atlantic Ocean to the east, the North Pacific Ocean to the west, Mexico and the Gulf of Mexico to the south, and Canada to the north. The state of Alaska also borders Canada, with the Pacific Ocean to its south and the Arctic Ocean to its north. West of Alaska, across the narrow Bering Strait, is Russia. The state of Hawaii occupies an archipelago in the Pacific Ocean, southwest of the North American mainland.


The U.S. has an extremely varied geography, particularly in the West. The eastern seaboard has a coastal plain which is widest in the south and narrows in the north. The coastal plain does not exist north of New Jersey, although there are glacial outwash plains on Long Island, Martha's Vineyard, and Nantucket. In the extreme southeast, Florida is home to the ecologically unique Everglades.

Beyond the coastal plain, the rolling hills of the Piedmont region end at the Appalachian Mountains, which rise above 6,000  feet (1,830  m) in North Carolina, Tennessee, and New Hampshire. From the west slope of the Appalachians, the Interior Plains of the Midwest are relatively flat and are the location of the Great Lakes as well as the Mississippi-Missouri River, the world's 4th longest river system. West of the Mississippi River, the Interior Plains slope uphill and blend into the vast and often featureless Great Plains.

The abrupt rise of the Rocky Mountains, at the western edge of the Great Plains, extends north to south across the continental U.S., reaching altitudes over 14,000 feet (4,270 m) in Colorado. In the past, the Rocky Mountains had a higher level of volcanic activity; nowadays, the range only has one area of volcanism (the supervolcano underlying Yellowstone National Park in Wyoming, possibly the world's largest volcano), although rift volcanism has occurred relatively recently near the Rockies' southern margin in New Mexico.

Alaska has numerous mountain ranges, including Mount McKinley (Denali), the highest peak in North America. Numerous volcanoes can be found throughout the Alexander and Aleutian Islands extending south and west of the Alaskan mainland.

The Hawaiian islands are tropical, volcanic islands extending over 1,500  miles (2,400  km), and consisting of six larger islands and another dozen smaller ones that are inhabited.


Average precipitation
Average precipitation

Due to its large size and wide range of geographic features, the United States contains examples of nearly every global climate. The climate is temperate in most areas, tropical in Hawaii and southern Florida, polar in Alaska, semiarid in the Great Plains west of the 100th meridian, Mediterranean in coastal California and arid in the Great Basin. Its comparatively generous climate contributed (in part) to the country's rise as a world power, with infrequent severe drought in the major agricultural regions, a general lack of widespread flooding, and a mainly temperate climate that receives adequate precipitation.


Native Americans

Before the European colonization of the Americas, a process that began at the end of the 15th century, the present-day continental U.S. was inhabited exclusively by various indigenous tribes, including Alaskan natives, who migrated to the continent over a period that may have begun 35,000 years ago and may have ended as recently as 11,000 years ago.

European colonization

The Mayflower in Plymouth Harbor, painted by William Halsall, 1882.  the Mayflower transported Pilgrims to the New World in 1620.
The Mayflower in Plymouth Harbour, painted by William Halsall, 1882. the Mayflower transported Pilgrims to the New World in 1620.

The first confirmed European landing in the present-day United States was by Christopher Columbus, who visited Puerto Rico on November 19, 1493, during his second voyage. San Juan, the United States' first European settlement was founded there on August 8, 1508 by Juan Ponce de León. Ponce de León went on to become the first confirmed European to arrive in the continental US when he landed in Florida on April 2, 1513. Florida was home to the continental United States' earliest European colonies; these were Pensacola (founded by Tristán de Luna y Arellano in 1559), Fort Caroline (by René Goulaine de Laudonnière in 1564), and St. Augustine (by Pedro Menéndez de Avilés in 1565), the last of which is the only one which was continuously inhabited since its foundation.

The French colonized some of the northeastern portions, and the Spanish colonized most of the southern and western United States. The first successful English settlement was at Jamestown, Virginia, in 1607, followed in 1620 by the Pilgrims' landing at Plymouth, Massachusetts, then the arrival of the colony of Massachusetts Bay, started by the Puritans. In 1609 and 1617, respectively, the Dutch settled in part of what became New York and New Jersey. In 1638, the Swedes founded New Sweden, in part of what became Delaware, New Jersey, and Pennsylvania after passing through Dutch hands. Throughout the 17th and early 18th centuries, England (and later Great Britain) established new colonies, took over Dutch colonies, and split others. With the division of the Carolinas in 1729, and the colonization of Georgia in 1732, the British colonies in North America—excluding present-day Canada, and the loyal colonies of East and West Florida—numbered thirteen.

American Revolution

The drafting committee presenting the Declaration of Independence to the Continental Congress. Painted by John Trumbull 1817–1819.
The drafting committee presenting the Declaration of Independence to the Continental Congress. Painted by John Trumbull 1817–1819.

Tensions between American colonials and the British during the revolutionary period of the 1760s and 1770s led to open military conflict in 1775. George Washington commanded the Continental Army during the American Revolutionary War (1775–1783) as the Second Continental Congress adopted the Declaration of Independence on July 4, 1776. The Congress had been formed to confront British actions and created the Continental Army, but it did not have the authority to levy taxes or make federal laws. In 1777, the Congress adopted the Articles of Confederation, uniting the states under a weak federal government, which operated from 1781 until 1788, when enough states had ratified the United States Constitution. The Constitution, which strengthened the union and the federal government, has since remained the supreme law of the land and holds the record for the set of laws to stay in effect the longest in the world.

Westward expansion

National Atlas map depicting dates of select territorial acquisitions. Full Oregon and other claims are not included.
National Atlas map depicting dates of select territorial acquisitions. Full Oregon and other claims are not included.

From 1803 to 1848, the size of the new nation nearly tripled as settlers (many embracing the concept of Manifest Destiny as an inevitable consequence of American exceptionalism) pushed beyond national boundaries even before the Louisiana Purchase. The expansion was tempered somewhat by the stalemate in the War of 1812, but it was subsequently reinvigorated by victory in the Mexican-American War in 1848.

Between 1830-1880 up to 40 million American Buffalo were slaughtered for skins and meat, and to aid railway expansion. The expansion of the railways reduced transit times for both goods and people, made westard expansion less arduous for the pioneers, and increased conflicts with the Indians over the land and its uses. The loss of the buffalo, a primary resource for the plains Indians, added to the pressures on native cultures and individuals for survival.

Civil War

The Battle of Gettysburg color lithograph by Currier & Ives, c. 1863. This battle was a major turning point of the American Civil War. The victory of the Union kept the country united.
The Battle of Gettysburg colour lithograph by Currier & Ives, c. 1863. This battle was a major turning point of the American Civil War. The victory of the Union kept the country united.

As new territories were being incorporated, the nation was divided over the issue of states' rights, the role of the federal government, and—by the 1820s—the expansion of slavery, which had been legal in all thirteen colonies but was rarer in the north, where it was abolished by 1804. The Northern states were opposed to the expansion of slavery whereas the Southern states saw the opposition as an attack on their way of life, since their economy was dependent on slave labor. The failure to permanently resolve these issues led to the Civil War, following the secession of many slave states in the South to form the Confederate States of America after the 1860 election of Abraham Lincoln. The 1865 Union victory in the Civil War effectively ended slavery and settled the question of whether a state had the right to secede. The event was a major turning point in American history, with an increase in federal power.

Reconstruction and industrialization

Landing at Ellis Island
Landing at Ellis Island

After the Civil War, an unprecedented influx of immigrants, who helped to provide labor for American industry and create diverse communities in undeveloped areas—together with high tariff protections, national infrastructure building, and national banking regulations—hastened the country's rise to international power. The growing power of the United States enabled it to acquire new territories, including the annexation of Puerto Rico after victory in the Spanish-American War, which marked the debut of the United States as a major world power.

World War I and II

An abandoned farm in South Dakota during the Great Depression, 1936 Farm Security Administration photography by Sloan.
An abandoned farm in South Dakota during the Great Depression, 1936 Farm Security Administration photography by Sloan.

At the start of the World War I in 1914, the United States remained neutral. In 1917, however, the United States joined the Allied Powers, helping to turn the tide against the Central Powers. For historical reasons, American sympathies were very much in favour of the British and French, even though a sizable number of citizens, mostly Irish and German, were opposed to intervention. After the war, the Senate did not ratify the Treaty of Versailles because of a fear that it would pull the United States into European affairs. Instead, the country pursued a policy of unilateralism that bordered at times on isolationism.

During most of the 1920s, the United States enjoyed a period of unbalanced prosperity as farm prices fell and industrial profits grew. A rise in debt and an inflated stock market culminated in a crash in 1929, triggering the Great Depression. After his election as President in 1932, Franklin Delano Roosevelt instituted his plan for a New Deal, which increased government intervention in the economy in response to the Great Depression.

The nation did not fully recover until 1941, when the United States was driven to join the Allies against the Axis Powers after a surprise attack on Pearl Harbour by Japan. World War II was the costliest war in economic terms in American history, but it helped to pull the economy out of depression because the required production of military materiel provided much-needed jobs, and women entered the workforce in large numbers for the first time. During this war, scientists working for the United States federal government succeeded in producing nuclear weapons, making the United States the world's first nuclear power. Toward the end of World War II, after the end of World War II in Europe, the United States dropped atomic bombs on Hiroshima and Nagasaki, Japan. The Hiroshima and Nagasaki bombs were the second and third nuclear devices detonated and the only ones ever employed as weapons.

Japan surrendered soon after, on 2 September 1945, which ended World War II.

Cold War and civil rights

After World War II, the United States and the Soviet Union became superpowers in an era of ideological rivalry dubbed the Cold War. The United States promoted liberal democracy and capitalism, while the Soviet Union communism and a centrally planned economy. The result was a series of proxy wars, including the Korean War, the Vietnam War, the tense nuclear showdown of the Cuban Missile Crisis, and the Soviet war in Afghanistan.

The perception that the United States was losing the space race spurred government efforts to raise proficiency in mathematics and science in schools and led to President John F. Kennedy's call for the United States to land "a man on the moon" by the end of the 1960s, which was realized in 1969.

Meanwhile, American society experienced a period of sustained economic expansion. At the same time, discrimination across the United States, especially in the South, was increasingly challenged by a growing civil-rights movement headed by prominent African Americans such as Martin Luther King, Jr., which led to the abolition of the Jim Crow laws in the South.

After the fall of the Soviet Union in 1991, the United States continued to intervene in overseas military conflicts such as the Gulf War. It remains the world's only superpower.

September 11, 2001 and the War on Terrorism

On September 11, 2001, 19 al-Qaeda operatives hijacked four commercial airplanes and flew two planes into the World Trade Centre towers, one plane into The Pentagon; the fourth plane was brought down by passengers in Shanksville, Pennsylvania. After the 9/11 attacks, U.S. foreign policy then focused on the global threat of terrorism. In response, the United States government under President George W. Bush began a series of military and legal operations termed the War on Terror. The War on Terror began on October 7, 2001 when a U.S.-led coalition launched military operations in Afghanistan which led to the removal of the Taliban rule and the expulsion of the terrorist organization al-Qaeda and its leader Osama Bin Laden. The events of September 11 led to a preemptive policy against threats to U.S. security, known as the Bush Doctrine.

In the 2002 State of the Union address, President George W. Bush labeled North Korea, Iraq, and Iran "the axis of evil," and stated that these countries "constitute a grave threat to the security of the U.S. and its allies." Beginning later that year, the Bush administration began to press for regime change in Iraq. After many failed U.N. resolutions and Saddam Hussein rejecting demands to surrender, the United States and its allies invaded Iraq in March of 2003. The Bush administration justified its invasion with a charge that Iraq had stockpiled weapons of mass destruction, and was seeking nuclear weapons. After the invasion, only a limited number of non-nuclear stockpiles were found, and the Bush administration later admitted having acted on flawed intelligence. As of November 2006, Operation Iraqi Freedom remains an ongoing event.

Government and politics

West Front of the United States Capitol.
West Front of the United States Capitol.

Political system

The United States is the longest-surviving extant constitutional republic, with the oldest wholly written constitution in the world. Its government operates as a representative democracy through a congressional system under a set of powers specified by its Constitution. There are three levels of government: federal, state, and local. Officials at all three levels are either elected by voters in a secret ballot or appointed by other elected officials. Executive and legislative offices are decided by a plurality vote of citizens in their respective districts, with judicial and cabinet-level offices nominated by the Executive branch and approved by the Legislature. In some states, judicial posts are filled by popular election rather than executive appointment.

The federal government comprises three branches, which are designed to check and balance one another's powers:

  • Legislative: The Congress, made up of the Senate and the House of Representatives, which makes federal law, declares war, approves treaties and has powers of impeachment.
  • Executive: The President, who appoints, with Senate approval, the Cabinet and other officers, who administers and enforces federal law, can veto bills, and is Commander in Chief of the military.
  • Judiciary: The Supreme Court and lower federal courts, whose judges are appointed by the President with Senate approval, that interpret laws and their validity under the Constitution, and can overturn laws they deem unconstitutional.

The United States Congress is a bicameral legislature. The House of Representatives has 435 members, each representing a congressional district for a two-year term. House seats are apportioned among the states according to population every tenth year. Each state is guaranteed at least one representative: currently, seven states have one each; California, the most populous state, has 53. Each state has two senators, elected at large to six-year terms; one third of Senate seats are up for election every second year.

The north side of the White House
The north side of the White House

The United States Constitution is the supreme legal document in the American system, and serves as a social contract between the people of the United States and their government. All laws and procedures of both state and federal governments are subject to review, and any law ruled to violate the Constitution by the judicial branch is overturned. The Constitution is a living document. It can be amended by a variety of methods, all of which require the approval of an overwhelming majority of the states. The Constitution has been amended 27 times, the last time in 1992.

The Constitution contains a dedication to "preserve liberty" with a "Bill of Rights" and other amendments, which guarantee freedom of speech, religion, and the press; the right to a fair trial; the right to keep and bear arms; universal suffrage; and property rights. However, the extent to which these rights are protected and universal in practice is heavily debated. The Constitution also guarantees to every State "a Republican Form of Government". However, the meaning of that guarantee has been only slightly explicated.

Since 2001, the President has been George W. Bush, a Republican. Following the 2006 mid-term elections, the Democratic Party holds a majority of seats in both the House and Senate for the first time since 1994, except for a Democratic plurality in the Senate in 2001–02,

Foreign relations and military

The United States has vast economic, political, and military influence on a global scale, which makes its foreign policy a subject of great interest and discussion around the world. Almost all countries have embassies in Washington, D.C., and consulates around the country. However, Cuba, Iran, North Korea, and Sudan do not have formal diplomatic relations with the United States. The United States is a founding member of the United Nations (with a permanent seat on the Security Council), among many other international organizations.

The United States has a long-standing tradition of civilian control over military affairs. The Department of Defense administers the U.S. armed forces, which comprise the Army, the Navy, the Marine Corps, and the Air Force. The Coast Guard falls under the jurisdiction of the Department of Homeland Security in peacetime but is placed under the Department of the Navy in times of war.

The military of the United States comprises 1.4 million personnel on active duty, along with several hundred thousand each in the Reserves and the National Guard. Service in the military is voluntary, though conscription may occur in times of war through the Selective Service System. The United States is considered to have the most powerful military in the world, partly because of the size of its defense budget; American defense expenditures in 2005 were estimated to be greater than the next 14 largest national military budgets combined, even though the U.S. military budget is only about 4% of the country's gross domestic product. The U.S. military maintains over 700 bases and facilities on every continent except Antarctica.

Administrative divisions

Map of United States, showing state names.
Map of United States, showing state names.

The conterminous, or contiguous, forty-eight states—all the states but Alaska and Hawaii—are also called the continental United States. Some include Alaska in the "continental" states, because, although it is separated from the "lower forty-eight" by Canada, it is part of the North American mainland. All of these terms commonly include the District of Columbia. Hawaii, the fiftieth state, occupies an archipelago in the Pacific Ocean.

The United States also holds several other territories, districts, and possessions, notably the federal district of the District of Columbia—which contains the nation's capital city, Washington—and several overseas insular areas, the most significant of which are American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the United States Virgin Islands. Palmyra Atoll is the United States' only incorporated territory; but it is unorganized and uninhabited. The United States Minor Outlying Islands consist of uninhabited islands and atolls in the Pacific and Caribbean Sea. In addition, since 1898, the United States Navy has leased an extensive naval base at Guantanamo Bay, Cuba.

In addition to the actual states and territories of the United States, there are also nations which are associated states of the U.S. The Federated States of Micronesia (since 1986), Palau (since 1994), and the Marshall Islands (since 1986) are associated with the United States under what is known as the Compact of Free Association, giving the states international sovereignty and ultimate control over their territory. However, the governments of those areas have agreed to allow the United States to provide defense and financial assistance.


The Bald Eagle appears on the Great Seal of the United States. Protection of this once endangered species has helped save it from extinction.
The Bald Eagle appears on the Great Seal of the United States. Protection of this once endangered species has helped save it from extinction.

The U.S. has over 17,000 identified native plant and tree species, including 5,000 just in California (which is home to the tallest, the most massive, and the oldest trees in the world). With habitats ranging from tropical to arctic, the flora of the U.S. is the most diverse of any country; yet, thousands of non-native exotic species sometimes adversely affect indigenous plant and animal communities. Over 400 species of mammal, 700 species of bird, 500 species of reptile and amphibian, and 90,000 species of insect have been documented. Many plants and animals are very localized in their distribution, and some are in danger of extinction. The U.S. passed the Endangered Species Act in 1973 to protect native plant and animal species and their habitats.

Conservation has a long history in the U.S.; in 1872, the world's first National Park was established at Yellowstone. Another 57 national parks and hundreds of other federally managed parks and forests have since been designated. In some parts of the country, wilderness areas have been established to ensure long-term protection of pristine habitats. The U.S. Fish and Wildlife Service monitors endangered and threatened species and has set aside numerous areas for species and habitat preservation. Altogether, the U.S. government regulates 1,020,779 square miles (2,643,807 km²), which is 28.8% of the total land area of the U.S. The bulk of this land is protected park and forestland, but some is leased for oil and gas exploration, mining, and cattle ranching.


General situation

The economic history of the United States is a story of economic growth that began with marginally successful colonial economies and progressed to the largest industrial economy in the world in the 20th and early 21st century.

The New York Stock Exchange on Wall Street, in New York City, represents the status of the U.S. as a major global financial power.
The New York Stock Exchange on Wall Street, in New York City, represents the status of the U.S. as a major global financial power.

The economic system of the United States can be described as a capitalist mixed economy, in which corporations, other private firms, and individuals make most microeconomic decisions, and governments prefer to take a smaller role in the domestic economy, although the combined role of all levels of government is relatively large, at 36% of the Gross Domestic Product (GDP). The U.S. has a small social safety net, and regulation of businesses is slightly less than the average of developed countries. The United States' median household income in 2005 was $43,318.

Economic activity varies greatly across the country. For example, New York City is the centre of the American financial, publishing, broadcasting, and advertising industries, while Los Angeles is the most important centre for film and television production. The San Francisco Bay Area and the Pacific Northwest are major centers for technology. The Midwest is known for its reliance on manufacturing and heavy industry, with Detroit serving as the historic centre of the American automotive industry, and Chicago serving as the business and financial capital of the region. The Southeast is a major area for agriculture, tourism, and the lumber industry, and, because of wages and costs below the national average, it continues to attract manufacturing.

A farm near Klingerstown, Pennsylvania. Farming accounts for less than 1% of the total GDP of the United States but still is a major economic activity.
A farm near Klingerstown, Pennsylvania. Farming accounts for less than 1% of the total GDP of the United States but still is a major economic activity.

The largest sector in the United States economy is services, which employs roughly three quarters of the work force.

The economy is fueled by an abundance in natural resources such as coal, petroleum, and precious metals. However, the country still depends for much of its energy on foreign countries. In agriculture, the country is a top producer of corn, soy beans, rice, and wheat, with the Great Plains labeled as the "breadbasket of the world" for its tremendous agricultural output. The U.S. has a large tourist industry, ranking third in the world, and is also a major exporter in goods such as airplanes, steel, weapons, and electronics. Canada accounts for 19% (more than any other nation) of the United States' foreign trade, followed by China, Mexico, and Japan.

While the per capita income of the United States is among the highest in the world, the wealth is comparatively concentrated. The per capita income is higher than the western European, but in 1990 income was distributed less equally. Since 1975, the U.S. has a "two-tier" labor market in which virtually all the real income gains have gone to the top 20% of households, with most of those gains accruing to the very highest earners within that category. This polarization is the result of a relatively high level of economic freedom.

The social mobility of U.S. residents relative to that of other countries is the subject of much debate. Some analysts have found that social mobility in the United States is low relative to other OECD states, specifically compared to Western Europe, Scandinavia and Canada. Low social mobility may stem in part from the U.S. educational system. Public education in the United States is funded mainly by local property taxes supplemented by state revenues. This frequently results in a wide difference in funding between poor districts or poor states and more affluent jurisdictions. In addition, the practice of legacy preference at elite universities gives preference to the children of alumni, who are often wealthy. This practice reduces available spaces for better-qualified lower income students. Some analysts argue that relative social mobility in the U.S. peaked in the 1960s and declined rapidly beginning in the 1980s. Former Federal Reserve Board Chairman Alan Greenspan has also suggested that the growing income inequality and low class mobility of the U.S. economy may eventually threaten the entire system in the near future.


The Space Shuttle Columbia takes off on a manned mission to space.
The Space Shuttle Columbia takes off on a manned mission to space.

The United States is an influential country in scientific and technological research and the production of innovative technological products. During World War II, the U.S. was the first to develop the atomic bomb, ushering in the atomic age. Beginning early the Cold War, the U.S. achieved successes in space science and technology, leading to a space race which led to rapid advances in rocketry, weaponry, material science, computers, and many other areas. This technological progress was epitomized by the first visit of a man to the moon, when Neil Armstrong stepped off of Apollo 11 in July 1969. The U.S. was also the most instrumental nation in the development of the Internet, developing its predecessor, Arpanet. The U.S. also controls most of its infrastructure.

In the sciences, Americans have a large share of Nobel Prizes, especially in the fields of physiology and medicine. The National Institutes of Health, a focal point for biomedical research in the United States, has contributed to the completion of the Human Genome Project. The main governmental organization for aviation and space research is the National Aeronautics and Space Administration. Major corporations, such as Boeing and Lockheed Martin, also play an important role.


The automobile industry developed earlier and more rapidly in the United States than in most other countries. The backbone of the nation's transportation infrastructure is a network of high-capacity highways which carry large numbers of both passenger cars and freight trucks. From data taken in 2004, there are about 3,981,521 miles (6,407,637  km) of roadways in the U.S., the most in the world.

Mass transit systems exist in large cities, such as New York, which operates one of the busiest subway systems in the world. With a few exceptions, American cities are less dense than those in other parts of the world. Low density partly results from and largely necessitates automobile ownership by most households.

The U.S. had been unique in its high number of private passenger railroads. During the 1970s, government intervention reorganized freight railroads, consolidating passenger service under the government-backed Amtrak corporation. No other country has more miles of rail.

Air travel is the preferred means of passenger travel for long distances. In terms of passengers, seventeen of the world's thirty busiest airports in 2004 were in the U.S., including the world's busiest, Hartsfield–Jackson Atlanta International Airport (ATL). In terms of cargo, in the same year, twelve of the world's thirty busiest airports were in the U.S., including the world's busiest, Memphis International Airport.

Several major seaports are in the United States; the three busiest are California's Port of Los Angeles and Port of Long Beach, and the Port of New York and New Jersey, all among the world's busiest. The interior of the U.S. also has major shipping channels, via the St. Lawrence Seaway and the Mississippi River. The first water link between the Great Lakes and the Atlantic, the Erie Canal, allowed the rapid expansion of agriculture and industry in the Midwest and made New York City the economic centre of the country.


2000 Population Density Map
2000 Population Density Map

On October 17, 2006 at 7:46 a.m. EST, the United States' population stood at an estimated 300,000,000, with an annual growth rate of about 0.59%. This figure includes persons living in the U.S. without legal permission to do so, estimated at 12 million, and excludes U.S. citizens living abroad, estimated at 3 million to 7 million. Thus any population estimate needs to be seen as a somewhat rough figure, according to the US Department of Commerce. According to the 2000 census, about 79% of the population lived in urban areas.

About 15.8% of households have annual incomes of at least $100,000, and the top 10% of households had annual gross incomes exceeding $118,200 in 2003. Overall, the top quintile, those households earning more than $86,867 a year, earned 49.8% of all income in 2003.

In the 2000 census, the country had 31 ethnic groups with at least one million members each, with numerous others represented in smaller amounts. By the federal government's categorization of race, most Americans (80.4% in 2004) are white. These white Americans are mostly European Americans—the descendants of European immigrants to the United States—along with some non-Europeans counted as white in government nomenclature (those with origins in the original peoples of the Middle East and North Africa). To the exclusion of Hispanic-origin European Americans, non-Hispanic whites constituted 67.4% of the population. The non-Hispanic white population is proportionally declining, because of both immigration by, and a higher birth rate among, ethnic and racial minorities. If current immigration trends continue, the number of non-Hispanic whites is expected to be reduced to a plurality by 2040-2050. The largest ethnic group of European ancestry is German at 15.2%, followed by Irish (10.8%), English (8.7%), Italian (5.6%) and Scandinavian (3.7%). Many immigrants also hail from French Canada, as well as from such Slavic countries as Poland and Russia. African Americans, or Blacks, largely descend from Africans who arrived as slaves during the 17th through 19th centuries, and number about 35 million or 12.9% of the population. At about 1.5% of the total population, Native Americans and Alaska Natives number about 4.4 million, approximately 35% of whom were living on reservations in 2005.

Current demographic trends include the immigration of Hispanics from Latin America into the Southwest, a region that is home to about 60% of the 35 million Hispanics in the United States. Immigrants from Mexico make up about 66% of the Hispanic community, and are second only to the German-descent population in the single-ethnicity category. The Hispanic population, which has been growing at an annual rate of about 4.46% since the 1990s, is expected to increase significantly in the coming decades, because of both immigration and a higher birth rate among Latinos than among the general population.

Crime in the United States is characterised by relatively high levels of gun violence and homicide, compared to other developed countries. Levels of property crime and other types of crime in the United States are comparable to other developed countries.

Largest cities

The United States has dozens of major cities, which play an important role in U.S. culture, heritage, and economy. In 2004, 251 incorporated places had populations of at least 100,000 and nine had populations greater than 1,000,000, including several important global cities, such as New York City, Los Angeles, and Chicago. In addition, there are fifty metropolitan areas with populations over 1,000,000.

Indigenous peoples

Chief Quanah Parker.
Chief Quanah Parker.

The Indian Citizenship Act of 1924 gave United States citizenship to Native Americans, in part because of an interest by many to see them merged with the American mainstream, and also because of the heroic service of many Native American veterans in the First World War.

According to the 2003 census estimates, there are 2,786,652 Native Americans in the United States. However, numerous indigenous peoples from Latin American countries, particularly Mexico, have migrated to the U.S. over the years.


Although the United States has no official language, English is the de facto national language. In 2003, about 215 million, or 82%, of the population aged five years and older spoke only English at home. Although not all Americans speak English, it is the most common language for daily interaction among both native and non-native speakers. Nowadays, more languages are being used in daily life for mainly Spanish speakers who cannot understand English. Knowledge of English is required of immigrants seeking naturalization. Some Americans advocate making English the official language, which is the law in twenty-seven states. Three states also grant official status to other languages alongside English: French in Louisiana, Hawaiian in Hawaii, and Spanish in New Mexico. Besides English, languages spoken at home by at least one million Americans aged five years and up are Spanish or Spanish Creole, spoken by 29.7 million; Chinese, 2.2 million; French (including Patois and Cajun), 1.4 million; Tagalog, 1.3 million; Vietnamese, 1.1 million; and German, 1.1 million.


Pisgah Baptist Church in Four Oaks, North Carolina. The Bible Belt is well known for its large devout Protestant Christian population.
Pisgah Baptist Church in Four Oaks, North Carolina. The Bible Belt is well known for its large devout Protestant Christian population.

The United States government keeps no official register of Americans' religious status. However, in a private survey conducted in 2001 and mentioned in the Census Bureau's Statistical Abstract of the United States, 76.7% of American adults identified themselves as Christian; about 52% of adults described themselves as members of various Protestant denominations. Roman Catholics, at 24.5%, were the most populous individual denomination. The most popular other faiths include Judaism (1.4%), Islam (0.6%), Buddhism (0.5%), and Hinduism (0.4%) and Unitarian Universalism (0.3%). About 14.2% of respondents described themselves as having no religion. The religious distribution of the 5.4% who elected not to describe themselves for the survey is unknown.

Religion among some Americans is highly dynamic: over the period 1990–2001, those groups whose portion of the population at least doubled were, in descending order of growth, Wiccans, nondenominational Christians, Deists, Sikhs, Evangelical Christians, Disciples of Christ, New Age adherents, Hindus, Full Gospel adherents, Quakers, Bahá'ís, independent Christians, those who refused to answer the question, Buddhists, and Foursquare Gospel adherents.


The University of Virginia, designed and founded by Thomas Jefferson, is one of 19 UNESCO World Heritage Sites in the United States. It is one of many highly regarded public universities supported by U.S. state governments.
The University of Virginia, designed and founded by Thomas Jefferson, is one of 19 UNESCO World Heritage Sites in the United States. It is one of many highly regarded public universities supported by U.S. state governments.

Education in the United States has been a state or local, not federal, responsibility. The Department of Education of the federal government, however, exerts some influence through its ability to control funding. Students are generally obliged to attend school starting with kindergarten, and ending with the 12th grade, which is normally completed at age 18, but many states may allow students to drop out as early as age 16. Besides public schools, parents may also choose to educate their own children at home or to send their children to parochial or private schools. After high school, students may choose to attend universities, either public or private. Public universities receive funding from the federal and state governments, as well as from other sources, but most students still have to pay student loans after graduation. Tuition at private universities is generally much higher than at public universities.

There are many competitive institutions of higher education in the United States, both private and public. The United States has 168 universities in the world's top 500, 17 of which are in the top 20. There are also many smaller universities and liberal arts colleges, and local community colleges of varying quality across the country with open admission policies.

The United States ranks 24th out of 29 surveyed countries in the reading and science literacy as well as mathematical abilities of its high school students when compared with other developed nations. The United States also has a low literacy rate compared to other developed countries, with a reading literacy rate at 86 - 98% of the population over age 15. As for educational attainment, 27.2% of the population aged 25 and above have earned a bachelor's degree or higher, and 84.6% have graduated high school.


The World Health Organization ranks the United States' health level 72nd among the world's nations. Overall statistics provided by the CIA World Factbook indicate that the United States had a higher infant mortality rate and slightly lower life expectancy than other post-industrial western nations such as Sweden, Germany or France. Ironically, the average salary of a physician in the US is the highest in the world. Obesity is also a public-health problem, which is estimated to cost tens of billions of dollars every year.

Unlike many Western governments, the U.S. government does not operate a publicly funded health care system. Private insurance plays a major role in covering health care costs. Health insurance in the United States is traditionally a benefit of some kinds of employment. However, emergency care facilities are required to provide service regardless of the patient's ability to pay. Medical bills are the most common reason for personal bankruptcy in the United States. The nation spends a substantial amount on medical research through such federal agencies as the National Institutes of Health.


Elvis Presley in 1957
Elvis Presley in 1957
American cultural icons, such as apple pie, baseball, and the American flag.
American cultural icons, such as apple pie, baseball, and the American flag.

The culture of the United States began as the culture of its first English colonists. The culture quickly evolved as an independent frontier culture supplemented by indigenous and Spanish–Mexican cowboy culture and by the cultures of subsequent waves of immigrants, first from Europe and Africa and later from Asia. Overall, significant cultural influences came from Europe, especially from the German, English and Irish cultures and later from Italian, Greek and Ashkenazi cultures. Descendants of enslaved West Africans preserved some cultural traditions from West Africa in the early United States. Geographical place names largely reflect the combined English, Dutch, French, Spanish, and Native American components of U.S. American history.

There are two dominant sociological models of cultural assimilation. The traditional melting pot model describes a form of homogenization. Immigrants from other cultures bring unique cultural aspects which are incorporated into the larger American culture, but then the immigrant populations gradually adopt the unified culture, forming a single "alloy". A more recently articulated model is that of the salad bowl, in which immigrant cultures retain some of the unique characteristics. Instead of merging with a unified American culture, they intermingle, forming a heterogenous mixture, not unlike a salad composed of different vegetables. There is considerable contemporary political debate over the merits of cultural assimilation versus pluralism or multiculturalism.

An important component of American culture is the American Dream: the idea that, through hard work, courage, and self-determination, regardless of social class, a person can gain a better life.


American cuisine uses Native American ingredients such as turkey, potatoes, corn, and squash, which have become integral parts of American culture. Such popular icons as apple pie, pizza, and hamburgers are either derived from or are actual European dishes. Burritos and tacos have their origins in Mexico. Soul food, which originated among African slaves, is popular in the U.S. as well. However, many foods now enjoyed worldwide either originated in the United States or were altered by American chefs.

Visual arts

In the eighteenth and early nineteenth centuries American art took most of its cues from Europe. Painting, sculpture, and literature looked to Europe as a model, and for approval. By the end of the U.S. Civil War, a more native voice had emerged in American literature. Mark Twain, Emily Dickensen, and Walt Whitman all spoke in an American vernacular and voice. Visual art was slower to find its own distinct American expression. The 1913 Armory show in New York City, an exhibition which brought European modernist artists' work to the U.S., both shocked the public and influenced artmaking in the United States for the remainder of the twentieth century. The exhibition had a two-fold effect of communicating to American artists that artmaking was about expression, not only aesthetics or realism, and at the same time showing that Europe had abandoned its conservative model of ranking artists according to a strict academic hierarchy. This encouraged American artists to find a personal voice, and a modernist movement, responding to American civilization, emerged in the United States. Alfred Stieglitz (1864–1946), photographer, Charles Demuth (1883–1935) and Marsden Hartley (1877–1943), both painters, helped establish an American viewpoint in the fine arts. The Museum of Modern Art in New York, founded in 1929, became a showcase for American and International contemporary art. Following the conclusion of the Second World War, a shift occured with the decline of Paris as the world's art center and the emergence of New York as the centre of contemporary fine art for the U.S. and the world.


Music also traces to the country's diverse cultural roots through an array of styles. Rock, soul, hip hop, country, blues, and jazz are among the country's most internationally renowned genres. Since the late 19th century, popular recorded music from the United States has become increasingly known across the world, such that some forms of American popular music are heard almost everywhere.


The birth of cinema, as well as its development, largely took place in the United States. In 1878, the first recorded instance of sequential photographs capturing and reproducing motion was Eadweard Muybridge's series of a running horse, which the British-born photographer produced in Palo Alto, California, using a row of still cameras. Since then, the American film industry, based in Hollywood, California, has had a profound effect on cinema across the world. Other genres that originated in the United States and spread worldwide include the comic book and Disney's animated films.


Pro Bowl, 2006. American Football is the most popular spectator sport in the United States.
Pro Bowl, 2006. American Football is the most popular spectator sport in the United States.

Sports are a national pastime, and playing sports, especially American football, baseball, and basketball, is very popular at the high school level. Professional sports in the U.S. is big business and contains most of the world's highest paid athletes. The "Big Four" sports are baseball, American football, ice hockey, and basketball. Baseball is thought of "the national pastime"; but, since the early 1990s, American football has largely been considered the most popular sport in America. Hockey has also lost its popularity recently.

Other sports, including auto racing, lacrosse, soccer, golf, and tennis, have significant followings. The United States is among the most influential countries in shaping three popular board-based recreational sports: surfboarding, skateboarding, and snowboarding. Eight Olympiads have taken place in the United States; in medals won, the United States ranks third all-time in the Winter Games, with 218 (78 gold, 81 silver, and 59 bronze), and first in the Summer Games, with 2,321 (943 gold, 736 silver, and 642 bronze).


History Timeline ( Colonial Era | American Revolution | Westward Expansion | Civil War | World War I | Great Depression | World War II | Cold War | Vietnam War | Civil Rights) | Foreign relations | Military | Demographic and Postal history
Politics Law ( Constitution and Bill of Rights | Declaration of Independence) | Political parties ( Democrats & Republicans) | Elections ( Electoral College) | Political scandals | Political divisions | Red state vs. blue state divide
Government Federal agencies | Legislative branch (Congress: House | Senate) Executive branch ( President & Vice-President | Cabinet | Attorney-General | Secretary of State) | Law enforcement ( FBI | Intelligence: CIA | DIA | NIMA | NRO | NSA) | Judicial branch ( Supreme Court) | Military ( Army | Navy | Marines | Air Force | Coast Guard )
Geography Appalachian Mtns. | Rocky Mtns. | Grand Canyon | Great Plains | Midwest | The South | Mississippi River | New England | Mid-Atlantic | Northwest | Mountains | Valleys | Islands | Rivers | States | Cities | Counties | Regions | Extreme points | National Park System
Economy Banking | Companies | Standard of living | U.S. Dollar | Wall Street | Household income | Homeownership | Poverty | Federal Reserve
Society Demographics | U.S. Census Bureau | Languages | Religion | Social structure | Standard of living | Media | Education | Holidays | Folklore | Middle class | Educational attainment | Professional and working class conflict | Crime
Arts Music ( Classical | Folk | Popular) | Film & TV ( Hollywood) | Literature ( Poetry | Transcendentalism | Harlem Renaissance | Beat Generation) | Visual arts ( Abstract expressionism) | Cuisine | Dance | Architecture
Other United States territory | Communications | Transportation ( Highways and Interstates | Railroads) | Uncle Sam | Flag | American Dream | Media | Education | Tourism | Social issues ( Immigration | Affirmative action | Racial profiling | Human rights | War on Drugs | Pornography | Same-sex marriage | Prisons | Capital punishment) | Anti-Americanism | American exceptionalism | American Folklore | American English | United States Mexico barrier | Passenger vehicle transport

Political divisions of the United States
Capital District of Columbia
States Alabama | Alaska | Arizona | Arkansas | California | Colorado | Connecticut | Delaware | Florida | Georgia | Hawaii | Idaho | Illinois | Indiana | Iowa | Kansas | Kentucky | Louisiana | Maine | Maryland | Massachusetts | Michigan | Minnesota | Mississippi | Missouri | Montana | Nebraska | Nevada | New Hampshire | New Jersey | New Mexico | New York | North Carolina | North Dakota | Ohio | Oklahoma | Oregon | Pennsylvania | Rhode Island | South Carolina | South Dakota | Tennessee | Texas | Utah | Vermont | Virginia | Washington | West Virginia | Wisconsin | Wyoming
Insular areas American Samoa | Guam | Northern Mariana Islands | Puerto Rico | Virgin Islands
Minor outlying islands Baker Island | Howland Island | Jarvis Island | Johnston Atoll | Kingman Reef | Midway Atoll | Navassa Island | Palmyra Atoll | Wake Island

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