United States

!U.S. flag flying near the Capitol The United States flag flying near the United States Capitol The United States of America is a federal presidential constitutional republic founded on principles of individual liberty, limited government, separation of powers, and popular sovereignty, as outlined in its 1787 Constitution—the world's oldest written constitution still in use—and the Bill of Rights (1791). Comprising 50 states, the District of Columbia, five major territories, and smaller possessions, it spans 3,532,316 square miles (9,147,593 km²) primarily in North America, with Alaska in the northwest and Hawaii in the Pacific, bordering Canada and Mexico and featuring coastlines on the Atlantic, Pacific, and Arctic Oceans; its population stands at about 342.9 million as of 2025. The economy, the world's largest by nominal GDP at $31.82 trillion (2025 projection) and second by purchasing power parity, relies on technology, finance, and services, while defense spending of $997 billion in 2024 supports global projection via bases, NATO, and capabilities in air, sea, space, and nuclear domains. Since independence in 1776 and superpower status after World War II, it has driven innovations like ARPANET (Internet precursor), nuclear weapons, the transistor, and NASA space exploration, alongside soft power from cultural exports in film, music, and brands, within a federal system of bicameral Congress, independent judiciary, and president via Electoral College, amid debates on historical issues like slavery, polarization, immigration, and foreign policy. ## Etymology and National Identity

TheUnited States of America(USA), also known as theUnited States(U.S.) orAmerica, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States also asserts sovereignty over five major island territories and various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's third-largest land area and third-largest population, exceeding 341 million.