Hospital Corpsman First Class Cooper was a member of Company E, 2nd Battalion, 1st Marines, 1st Marine Division. He was Killed in Action while tending his wounded comrades near Kajon-ni, North Korea, on 14 September 1951 with chest wounds.

Cooper was awarded the Purple Heart, the Combat Action Ribbon, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation and the Republic of Korea War Service Medal.