The United States has territories.
The United States of America ( USA ) , commonly known as the United States ( U.S. ) or America , is a constitutional federal republic composed of 50 states , a federal district , five major self-governing territories , and various possessions . The U.S. territories are scattered about the Pacific Ocean and the Caribbean Sea . The United States emerged from 13 British colonies along the East Coast . The United States embarked on a vigorous expansion across North America throughout the 19th century , displacing Native American tribes , acquiring new territories , and gradually admitting new states until it spanned the continent by 1848 .