Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago. European colonization began in the 16th century. Following the French and Indian War, numerous disputes between Great Britain and the colonies led to the American Revolution, which began in 1775, and the subsequent Declaration of Independence in 1776.The war ended in 1783 with the United States becoming the first country to gain independence from a European power. The current constitution was adopted in 1788, with the first ten amendments, collectively named the Bill of Rights, being ratified in 1791 to guarantee many fundamental civil liberties.
Sweeping civil rights legislation, notably the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the Fair Housing Act of 1968, outlawed discrimination based on race or color. The end of the Cold War and the collapse of the Soviet Union in 1991 left the United States as the world’s sole superpower.
The United States is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States , and other international organizations.
Despite income and wealth disparities, the United States continues to rank very high in measures of socioeconomic performance, including average wage, median income , human development, per capita GDP, and worker productivity.
