There are 50 states in the United States of America. This number excludes the federal district of Washington, D.C., which is not a state. This number also does not include U.S. territories, which receive U.S. protection and social services while maintaining internal independence.
The first states admitted to the union were Delaware, Pennsylvania and New Jersey, which were all granted statehood in December 1787. Twelve more states were added between 1788 and 1792, and the union continued to add states every few years until 1912. Alaska and Hawaii became the last states admitted in 1959.