Dunham enlisted as a private in the
U.S. Army on January 18, 1942, at Fort Leavenworth, Kansas, and served in the
European Theatre of World War II with the 1830th Ordnance Supply and Maintenance Company, Aviation. During D-Day, this unit helped to support the
Ninth Air Force. Dunham and his brother were deployed to France six weeks after D-Day. Before the
Invasion of Normandy, the brothers once met accidentally as Stanley Dunham went in search of rations at a hotel in London, where his brother Ralph Dunham happened to be staying. Madelyn Dunham gave birth to their daughter
Stanley Ann Dunham, who was later known as Ann, at St. Francis Hospital in Wichita on November 29, 1942. During the war, Madelyn Dunham worked on a
Boeing B-29 assembly line in Wichita.