US

For alternative meanings, see the disambiguation page for US, USA, United States, or American.

United States of America

Flag Coat of Arms
Motto: E pluribus unum (1789 to present) (Latin: "Out of Many, One") In God We Trust (1956 to present)
Anthem: The Star-Spangled Banner
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  • President  • Vice President	Federal republic George W. Bush (R) Dick Cheney (R)
Independence  • Declared  • Recognized Constitution  • Completed  • Ratified  • Effective	From Great Britain July 4, 1776 September 3, 1783 September 17, 1787 May 23, 1788 March 4, 1789
Area  • Total  • Water (%)	9,631,418 km² (3rd) 4.87%
Population  • 2005 est.  • 2000 census  • Density	297,700,000 (3rd) 281,421,906 32/km² (140th)
GDP (PPP)  • Total  • Per capita	2005 estimate $12,589,600 million (1st) $42,367 (2nd)
HDI (2003)	0.944 (10th) – high
Currency	Dollar ($) (USD)
Time zone  • Summer (DST)	(UTC-5 to -10) (UTC-4 to -10)
Internet TLD	.us .gov .edu .mil .um
Calling code	+1

The United States of America is a country situated primarily in North America. It comprises 50 states and one federal district, and has several territories. It is also referred to, with varying formality, as the United States, the U.S., the U.S.A., the States, America, or (poetically) Columbia.

Since the mid-20th century, following World War II, the United States has emerged as a dominant global influence in economic, political, military, scientific, technological, and cultural affairs. Because of its influence, the U.S. is considered a superpower and, particularly after the Cold War, a hyperpower by some.

The country celebrates its founding date as July 4, 1776, when the Second Continental Congress — representing thirteen British colonies — adopted the Declaration of Independence that rejected British authority in favor of self-determination. However, the structure of the government was profoundly changed in 1789, when the states replaced the Articles of Confederation with the United States Constitution. The date on which each of the fifty states adopted the Constitution is typically regarded as the date that state "entered the Union" to become part of the United States.

History

Prehistory

American history began with the migration of people from Asia across the Bering land bridge approximately 12,000 years ago following large animals that they hunted into the Americas. These Native Americans left evidence of their presence in petroglyphs, burial mounds, and other artifacts. It is estimated that 2–9 million people lived in the territory now occupied by the U.S. before that population was greatly diminisehd by European contact and the foreign diseases it brought. Some advanced societies were the Anasazi of the southwest, who inhabited Chaco Canyon, and the Woodland Indians, who built Cahokia, located near present-day St Louis, a city with a population of 40,000 at its peak in AD 1200.

Colonization by Europe

External visitors had arrived before, but it was not until the discovery voyages of Christopher Columbus in the late 1400s and early 1500s that European nations began to explore the land in earnest and settle there permanently. See Colonialism.

During the 1500s and 1600s, the Spanish settled parts of the present-day Southwest and Florida. The first successful English settlement was at Jamestown, Virginia, also in 1607. Within the next two decades, several Dutch settlements, including New Amsterdam (the predecessor to New York City), were established in what are now the states of New York and New Jersey. In 1637, Sweden established a colony at Fort Christina (in what is now Delaware), but lost the settlement to the Dutch in 1655.

This was followed by extensive British settlement of the east coast. The British colonists remained relatively undisturbed by their home country until after the French and Indian War, when France ceded Canada and the Great Lakes region to Britain. Britain then imposed taxes on the 13 colonies to pay for the war. The colonists widely resented the taxes because they were denied representation in the British Parliament. Tensions between Britain and the colonists increased, and the thirteen colonies eventually rebelled against British rule.

Nationhood