During World War II, William Gardner became a U.S. Army Air Forces ACE, credited with shooting down 8 enemy aircraft in aerial combat. He returned to civilian life after the war, working as Chief of Flight Test for Curtiss Propeller Division of Wright Aeronautical Corporation until his retirement in 1984. In retirement he worked closely with the Air Force as a director at Sandia National Laboratories in Albuquerque, New Mexico.