The United States of America , commonly known as the United States or America, is a country primarily located in North America. It is a federal republic of 50 states and the federal capital district of Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclavic state of Alaska in the northwest and the archipelagic state of Hawaii in the Pacific Ocean. Indian country includes 574 federally recognized tribes and 326 Indian reservations with tribal sovereignty rights. The U.S. – Wikipedia