Territories of the United States on stamps discusses commemorative postal issues devoted to lands that have been ceded to the nation or purchased by treaty in conjunction with both war and peace. Thirteen states have been created from colonial territories, two from independent republics, four from previous states in the Union, and an additional thirty-one from United States territories.
Many aspects of acquisition, settlement and exploration have been celebrated on postage stamps. These are represented below in issues that appeared prior to 1978 (the images of subsequent stamps remain under copyright by the United States Postal Service and may not be reproduced).