A map from 1900 of the United States showing the territorial expansion from the original Thirteen Colonies to the states and territories of 1900. The map is color-coded to show the original states, states admitted between 1791 and 1860, states admitted between 1861 and 1900, and the territories in 1900 (Arizona, New Mexico, Oklahoma and Indian Territory, and Alaska). Two inset maps detail Puerto Rico and Alaska, which also shows the gold bearing areas of the territory.