United States of America (USA)
The United States of America (U.S.A. or USA), commonly known as the United States is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, 326 Indian reservations, and some minor possessions.
It has 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 is New York City. Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago.
The United States is a federal republic and a representative democracy 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.
The U.S. ranks high in international measures of economic freedom, reduced levels of perceived corruption, quality of life, quality of higher education, and human rights. The United States is a highly developed country, and continuously ranks high in measures of socioeconomic performance.
It accounts for approximately a quarter of global GDP and is the world's largest economy by GDP at market exchange rates. The United States is the world's largest importer and the second-largest exporter of goods. The United States holds 29.4% of the total wealth in the world.