Joseph McKeon was born on September 14, 1916, in New York City, New York. He enlisted in the Aviation Cadet Program of the Army Air Corps on March 14, 1941, and was commissioned a 2Lt and awarded his pilot wings on October 31, 1941. McKeon was assigned to the 72nd Pursuit Squadron of the 15th Pursuit Group at Wheeler Field, Hawaii, in November 1941, and was there when Pearl Harbor was attacked by the Japanese on December 7, 1941. In August 1942, McKeon transferred to the 35th Fighter Squadron of the 8th Fighter Group in New Guinea where he flew P-39 Airacobra fighters, serving until March 1943 when he began flying P-38 Lightning fighters with the 80th Fighter Squadron. His next assignment was as Operations Officer of the 433rd Fighter Squadron, 475th Fighter Group, where he served from June to December 1943. During his time in the Pacific, McKeon was credited with destroying 5 enemy aircraft in aerial combat. He returned to the U.S. in December 1943, and after 3 months of leave, he was sent to Santa Maria Army Air Force Base, California, where he served as a P-38 instructor pilot. Capt McKeon was sent to England in July 1944, where he flew P-38 Lightning and P-51 Mustang fighters with the 55th Fighter Squadron of the 20th Fighter Group. He was credited with destroying 1 enemy aircraft before being forced to bail out over Germany on October 7, 1944. McKeon was captured the next day and taken as a Prisoner of War. He was released when Soviet troops liberated his POW camp on May 13, 1945. After the war, McKeon served at March Field, California, from December 1945 to November 1946 when he went on terminal leave. He left active duty on January 24, 1947, and returned to active duty on September 30, 1947, being assigned to the 524th Fighter Squadron at Kearney AFB, Nebraska, and then Bergstrom AFB, Texas. Maj McKeon was next assigned as Commanding Officer of the 559th Fighter Escort Squadron at Turner AFB, Georgia, and then at Bergstrom AFB, where he served from November 1950 to September 1952. He then served as Commander of the 468th Fighter Escort Squadron at Turner AFB, Georgia, from September 1952 to March 1954 when he was made Operations Staff Officer with the 508th Strategic Fighter Wing at Turner AFB. He served with the Military Assistance Advisory Group in France from August 1955 to April 1958. Col McKeon's final assignment was with Air Defense Command, where he served from April 1958 until his retirement from the Air Force on November 7, 1963.

His 3rd Distinguished Flying Cross Citation reads:

For heroism in flight and exceptional and outstanding accomplishment in the face of great danger above and beyond the line of duty during the period 24 September to 14 December 1943. These operations consisted of over fifty (50) missions including escorting bombers and transport aircraft, interception and attack missions, and patrol and reconnaissance flights. In the course of these operations, strafing and bombing attacks were made from dangerously low altitudes, destroying and damaging enemy installations and equipment.