The United States of America USA also known as the United States US or America is a country primarily located in North America It is a federal republic of 50 states and a federal capital district Washington DC The 48 contiguous states border Canada to the north and Mexico to the south with the semiexclave 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 Oc