On August 24, 1938, the Post Office Department issued a 3-cent violet stamp to commemorate the centennial of the establishment of the Iowa Territory. These lands had earlier been part of the Missouri, Michigan, and Wisconsin territories. The Iowa Territory included Iowa, parts of Minnesota, and the Dakotas. Iowa achieved statehood in 1846. The stamp depicts the Old Capitol in Iowa City, the territorial capital.
Gordon T. Trotter