Louis Mittendorf, Jr. served in the U.S. Army in the 85th Aero Squadron in World War I and saw action in France. He served as a Lieutenant in the Quartermaster Corps at Camp Ellis during World War II, in charge of the prisoner of war camp at Hooperston, Illinois. He died on May 12, 1945 in a car accident near Havana, Illinois. He was returning from Camp Ellis, where he was stationed when his car turned over and he was killed instantly.