Constituted as 322nd Bombardment Group (Medium) on 19 June 1942. Activated on 17 July 1942. Trained with B-26 aircraft. Part of the group moved overseas, Nov.-Dec. 1942; planes and crews followed, March-April 1943. Operated with Eighth AF until assignment to Ninth in Oct. 1943. Served in combat, May 1943-April 1945, operating from England France and Belgium. Began combat on 14 May when it dispatched 12 planes for a minimum-level attack on a power plant in Holland. Sent 11 planes on a similar mission three days later: one returned early; the others, with 60 crewmen, were lost to flak and interceptors. Trained for medium-altitude operations for several weeks and resumed combat on 17 July 1943. Received a DUC for the period 14 May 1943-24 July 1944, during which its combat performance helped to prove the effectiveness of the medium bombers.
Enemy airfields in France, Belgium, and Holland provided the principal targets from July 1943 through Feb. 1944, but the group also attacked power stations, shipyards, construction works, marshalling yards, and other targets. Beginning in March the 322nd bombed railroad and highway bridges, oil tanks, and missile sites in preparation for the invasion of Normandy; on 6 June 1944 it hit coastal defenses and gun batteries; afterward, during the Normandy campaign, it pounded fuel and ammunition dumps, bridges, and road junctions. Supported the Allied offensive at Caen and the breakthrough at St. Lo in July. Aided the drive of Third Army across France in Aug. and Sept. Bombed bridges, road junctions, defended villages, and ordnance depots in the assault on the Siegfried Line, Oct.-Dec. 1944. Flew a number of missions against railroad bridges during the Battle of the Bulge, Dec. 1944-Jan. 1945. Then concentrated on communications, marshalling yards, bridges, and fuel dumps until its last mission on 24 April 1945. Moved to Germany in June 1945. Engaged in inventorying and disassembling German Air Force equipment and facilities. Returned to the US, Nov.-Dec. 1945. Inactivated on 15 Dec. 1945.
Redesignated 322nd Bombardment Group (Light). Allotted to the reserve. Activated on 9 Aug. 1947. Inactivated on 27 June 1949.
Redesignated 322nd Fighter-Day Group, Activated on 1 July 1954. Assigned to Tactical Air Command. Equipped first with F-86 and later with F-100 aircraft.