Activated in September 1942. Trained with P-47 Thunderbolts under First Air Force in northeast United States. Deployed to European Theater of Operations, July 1943 as heavy bomber fighter escort squadron. Replaced Thunderbolts with long-range P-51D Mustangs, July 1944, P-47s reassigned to IX Fighter Command for tactical fighter-bomber missions supporting ground forces in France. Deployed to Belgium in December 1944 to supplement IX Fighter Command tactical air forces during Battle of the Bulge, Returned to England, engaging in long-range escort missions until April 1945.