Hospital Corpsman Chapman served with the U.S. Navy attached to Company D, 2nd Battalion, 1st Marines, 1st Marine Division. On 7 October 1952, he was Killed in Action while tending his wounded comrades in Korea by shrapnel wounds to his face and neck.

Chapman 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.