He fought in World War II with the 1st Infantry Division. As a major, he landed with the Big Red One in North Africa and two days later earned a Silver Star, America's third highest award for valor, for action in Oran, Algeria. Corley would pick up the first of his 8 Silver Stars when he braved heavy small arms fire to scout out observation points for artillery observers. In March 1943, during fighting at El Guettar, Tunisia, a well-entrenched machine gun nest halted the advance of his battalion, Corley crawled to its rear under heavy fire and personally threw the grenade that silenced the gun, allowing his troops to take the hilltop. This action earned Corley the Distinguished Service Cross, America's second highest award for valor. In May 1943 Corley was promoted to Lieutenant Colonel, just five years after graduating from West Point.