Joseph Sailer Jr. was the son of Dr. Joseph Sailer and Mary Lowber Strawbridge Sailer. He served in the Marine Corps Reserves in the 1930s, and later worked for the Sperry Gyroscope Company. In 1940, he traveled to England with Frederic Vose on a secret mission to provide the Royal Air Force with the Sperry Bomb Sight. Sailer and Vose are shown above, together, standing in front of an airplane before their trip to England. In World War II, Sailer was the leader of a squadron of Marine Corps dive-bomber pilots. He was killed in combat at Guadalcanal on December 7, 1942.