Corporal Allen was a veteran of World War II. In Korea, he was a member of Company C, 1st Battalion, 19th Infantry Regiment, 24th Infantry Division. He was Killed in Action while fighting the enemy at Taepyong-ni, South Korea on the Kum River on 16 July 1950.

Allen was awarded the Purple Heart, the Combat Infantryman Badge, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation, the Republic of Korea War Service Medal, the Asiatic Pacific Theater Medal and the World War II Victory Medal.