Activated as a B-26 Marauder Medium Bomber squadron in late 1942, it trained under Third Air Force in southeastern United States. Reassigned to European Theater of Operations in June 1943, it was first assigned to VIII Air Support Command, then to the IX Bomber Command in 1944. The squadron engaged in tactical bombardment of enemy targets in Occupied Europe, initially from stations in England. After D-Day, it moved to Advanced Landing Grounds in France and Belgium, advancing eastward along with the Allied ground forces. It supported Eighth Air Force strategic bombardment missions over Nazi Germany and Occupied Europe, striking enemy airfields to obtain maximum interference in Luftwaffe day interceptor attacks on heavy bomber formations.