The 373rd Fighter Group, composed of the 410th, 411th and 412th Fighter Squadrons, was constituted on 25 May 1943 and activated on 15 August 1943. The Group trained for combat on P-47's and went to England in March 1944 where it was assigned to the 9th Air Force. The Group flew its 1st combat mission on 8 May 1944, a fighter sweep over Normandy. It then took part in preinvasion activities, e.g., escorting B-26's to attack airdromes, bridges and railroads in France. The Group patrolled the air over the beachhead when the Allies launched the Normandy invasion on 6 June 1944, and hit troops, tanks, roads, fuel depots and other targets in the assault area until the end of the month.

The Group moved to the Continent in July 1944 where it struck railroads, hangars, boxcars, warehouses and other objectives to prevent reinforcements from reaching the front at St. Lo, where the Allies broke though on 25 July 1944. The Group bombed such targets as troops in the Falaise-Argentan area in August 1944. During the Battle of the Bulge, December 1944 - January 1945, the Group concentrated on the destruction of bridges, marshalling yards and highways. It flew reconnaissance missions to support ground operations in the Rhine Valley in March 1945, hitting airfields, motor transports, etc. The Group continued tactical air operations until 4 May 1945.

The 373rd Group retuned to the United States in August 1945. On 7 November 1945, the 373rd Fighter Group was inactivated.

last update: 10 Nov 04