The 315th continued to give close support to ground forces until the fall of Rome in June 1944. The group converted to Republic P-47 Thunderbolts in July and supported the assault on southern France in August by dive-bombing gun positions, bridges, and radar facilities, and by patrolling the combat zone. The unit attacked such targets as motor transport, rolling stock, rail lines, troops, bridges, gun emplacements, and supply depots after the invasion, giving tactical support to Allied forces advancing through France. The unit aided the reduction of the Colmar Pocket in January and February 1945, and supported Seventh Army's drive through the Siegfried defenses in March. It received the French Croix de Guerre with Palm for supporting French forces during the campaigns for Italy and France in 1944 and 1945.