Bongo Chongo Earth 91

The **United States of America** (**U.S.A.** or **USA**), commonly known as the **United States** (**U.S.** or **US**) or **America**, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, 326 Indian reservations, and nine minor outlying islands. At nearly 3.8 million square miles (9.8 million square kilometers), it is the world's third- or fourth-largest country by geographic area. The United States shares land borders with Canada to the north and Mexico to the south as well as maritime borders with the Bahamas, Cuba, Russia, and other countries. With a population of more than 331 million people, it is the third most populous country in the world. The national capital is Washington, D.C., and the most populous city and financial center is New York City.

Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago, and European colonization began in the 16th century. The United States emerged from the Thirteen British Colonies established along the East Coast. Disputes with Great Britain over taxation and political representation led to the American Revolutionary War (1775–1783), which established the nation's independence. In the late 18th century, the U.S. began expanding across North America, gradually obtaining new territories, sometimes through war, frequently displacing Native Americans, and admitting new states. This was strongly related to belief in manifest destiny, and by 1848, the United States spanned the continent from east to west. Slavery was legal in the southern United States until the second half of the 19th century, when the American Civil War led to its abolition. The Spanish–American War and World War I established the U.S. as a world power, and the aftermath of World War II left the United States and the Soviet Union as the world's two superpowers. During the Cold War, both sides fought in the Korean and Vietnam Wars but avoided direct military conflict. They competed in the Space Race, culminating in the 1969 American spaceflight that first landed humans on the Moon. The Soviet Union's dissolution in 1991 ended the Cold War, leaving the United States as the world's sole superpower.

The United States is a federal presidential-constitutional republic with three separate branches of government, including a bicameral legislature. It is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, NATO, and other international organizations. It is a permanent member of the United Nations Security Council. Considered a melting pot of cultures and ethnicities, its population has been profoundly shaped by centuries of immigration. The United States ranks high in international measures of economic freedom, quality of life, education, and human rights; it has low levels of perceived corruption. However, scholars have criticized it for racial, wealth, and income inequality, capital punishment and mass incarceration, and lack of universal health care.

The United States is a highly developed country, and its economy accounts for approximately a quarter of global GDP and is the world's largest by GDP at market exchange rates. By value, the United States is the world's largest importer and second-largest exporter of goods. Although its population is only 4.2% of the world's total, it holds over 30% of the total wealth in the world, the largest share held by any country. Making up more than a third of global military spending, it is the foremost military power in the world and a leading political, cultural, and scientific force.

## Contents

* 1Etymology
* 2History
	+ 2.1Indigenous peoples and pre-Columbian history
	+ 2.2European settlements
	+ 2.3Independence and expansion
	+ 2.4Civil War and Reconstruction era
	+ 2.5Further immigration, expansion, and industrialization
	+ 2.6World War I, Great Depression, and World War II
	+ 2.7Cold War and late 20th century
	+ 2.821st century
* 3Geography
	+ 3.1Biodiversity
* 4Government and politics
	+ 4.1Political divisions
	+ 4.2Parties and elections
	+ 4.3Foreign relations
	+ 4.4Government finance
	+ 4.5Military
	+ 4.6Law enforcement and crime
* 5Economy
	+ 5.1Science and technology
	+ 5.2Income, wealth, and poverty
	+ 5.3Transportation
	+ 5.4Energy
* 6Demographics
	+ 6.1Population
	+ 6.2Language
	+ 6.3Religion
	+ 6.4Health
	+ 6.5Education
* 7Culture
	+ 7.1Literature, philosophy, and visual art
	+ 7.2Food
	+ 7.3Music
	+ 7.4Cinema
	+ 7.5Theater
	+ 7.6Sports
	+ 7.7Mass media
* 8See also
* 9Notes
* 10References
* 11Further reading
* 12External links