He registered for the WW II draft and described himself as 5’10”, 145 lbs, with brown hair and eyes. He enlisted 17 September 1941 at Camp Blanding, Jacksonville, Florida as an aviation cadet. After training as a bombardier, he received his commission and wings. The bomber and crew were assigned to the 7th Bombardment Group, 436th Bombardment Squadron. He was the bombardier. It was last sighted by 1stLt Robert J. Clarke, 0-431388, 1stLt Robert G. Brittenbach, 0-659652, and 1stLt Henry W. Gilmer, Jr., 0-440853. 1stLt Clarke wrote, “It was last seen in formation with five other bombers entering a cloud bank. After fifteen minutes, the formation broke into the clear and only five aircraft could be accounted for. After another fifteen minutes, a crew hear, “Any B-24D for Help.” The call was answered but received no reply. An enemy fighter, type I45 (Kawasaki Toryu, for “Dragon Slayer,” allied name “Nick”), made an attack on a plane in the formation (not the missing bomber) and this was included to show there were enemy aircraft nearby.” Two search missions were flown. Called off because of poor weather. The bomber did not emerge from clouds with the other five on the mission. Enemy fighters were seen in the area; one attacked one of the B-24s. The bomber was not found. He was awarded the Distinguished Flying Cross, Air Medal and Purple Heart.
His family contributed more than their share. His brother, Dr. John C. McSween Jr., Lieutenant Colonel, 0-116329, served as a physician in the U.S. Army medical corps in Europe during WWII. Harry Y. McSween, Lieutenant Colonel, 0-410271, served during WW II (20 June 1941 - 5 August 1945) and through the Vietnam War era. Harry Y. McSween and John C. McSween are buried in the Magnolia Cemetery with other family.
11 July 1943 – Pensacola News Journal – Parents and friends are distressed because First Lt. Raymond “Dick” McSween is missing in action.
22 July 1943 – The Tampa Times – Tampa Day Times - Missing in action list included 2ndLt Ray D. McSween – Mrs. Grace Y. McSween of De Funiak Springs, FL.
27 August 1944 – Pensacola News Journal – Captain Harry McSween of De Funiak Springs was promoted to Major with the Fifth Army in Italy. He is battalion commander of the 34th “Red Bull” division on Fifth Army front. He entered the Army at Camp Croft, S.C. on 20 June 1941, 18 days after being commissioned at Presbyterian College. He has served as a platoon leader, company commander, battalion executive officer and course instructor in the Fifth Army battle school. He is a brother of Lt.Col. John C. McSween, medical corps, of Pensacola, and Lt. Raymond D. McSween, missing in action in Burma.
8 November 1944 – Injured Lt.Col. Harry McSween, 25, was wounded twice in the African campaign and returned to action in Italy. He has reached Charleston, S.C., from where he will be hospitalized for treatment. He is a brother of Lt.Col. (Dr.) John C. McSween of Pensacola who has been on duty in Iceland since June, 1942. Another brother, Lt. Raymond McSween, 27, was missing in action in Burma since last year. Lt.Col. Harry McSween has been cited for bravery several times, has several oak leaf clusters and promotion to Lt.Col. came after meritorious conduct for duty in Italian theater going into Rome. He commanded one of the first battalions into Rome.