Fort Des Moines is a National Historic Landmark—1 of only 2 in Polk County. It began as a cavalry post in 1901. 16 years later the Fort hosted a unique event—the training of black officers in the segregated U.S. Army during World War I. A second “first” occurred here during World War II when the Army broke gender barriers and allowed women to join the army as non-combat personnel. They became known as the Women’s Army Corps (WACs).