The United States of America (commonly referred to as the United States, the U.S., the Colonies, or America) is a federal constitutional republic comprising 72 states, a federal district, and 19 territories as of 1841. The country spans both American continents, where its thirty-eight contiguous states and Washington, D.C., the capital district, lie between the Pacific and Atlantic Oceans, bordered by the Arctic to the north and the South Sea to the south. The Greenland Territory is in the north-east of the continent.