The United States of America is a physically large country, occupying nearly 3.5 million square miles. Its population of more than 321 million persons is distributed unevenly across its physical area, with over half living in a state located on either its east or west coast. It comprises fifty states, two commonwealths, three territories, and a number of island entities variously called possessions or territories. In addition, there are currently 566 federally recognized Native American tribes, each of which has sovereign authority with respect to a limited range of matters. The capitol city of Washington, DC, is an independent district not located within any state; it has a local government and is also subject to federal authority in some areas.
