United States (Wikipedia) 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 in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. It is the world’s third-largest country by both land and total area. The United States shares land borders with Canada to its north and with Mexico to its south. It has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 331 million, it is the most populous country in the Americas and the third most populous in the world. The national capital is Washington, D.C., and the most populous city and financial center is New York City.