The William Dummer Powell World War II Collection consists of a small amount of textual materials and photographs primarily related to Powell's World War II service in the U.S. Army Air Forces.

The collection contains a small amount of military documents, including a booklet about the 449th Bomb Group, a 1944 Christmas dinner menu for the 449th Bomb Group, and a circa 1981-1989 certificate signed by President Ronald Reagan that honors the memory of Powell's service to the United States during World War II. There are also a selection of personal documents, including Powell's 1935 Certificate of Citizenship, a 1939 Certificate of Appreciation from the United States Junior Chamber of Commerce, a short essay written by Powell, Trail City, Cattle Town, circa 1940s-1950s, and a 1981 membership certificate for the Rocky Mountain Outdoor Writers and Photographers group.

Additionally, there are 25 black-and-white photographs. Many of the photographs have identifying captions on the front or back, although most people are identified by last name only. The images were taken in Taranto, Italy in 1944 and depict the men, including Powell, of the 449th Bomb Group, primarily involved in military activities, including three snapshots during the presentation of a Presidential Citation award. Aircraft are also featured, including a picture of the Consolidated B-24 Liberator "My Achin' Back" on the ground and four shots that show fire, flak, and turret damage to aircraft. Additionally, there is one shot of an Italian submarine with a handwritten caption on back "Taranto [Italy] 1944 - Italian sub entering inner harbor."