Gardiner Cornwell, Jr. served in the U.S. Army Air Corps as a Captain in the 98th Bomber Squadron, 11th Bomber Group, Heavy, in World War II. He was reported missing in action on April 27, 1943 when he disappeared in combat in the South Pacific. He was legally declared dead on December 15, 1945. He was awarded the Air Medal with two Oak Leaf Clusters and the Purple Heart.