Corporal Allen was a member of Company I, 3rd Battalion, 19th Infantry Regiment, 24th Infantry Division. He was Killed in Action while fighting the enemy near Taesong-ni, South Korea on 4 February 1951.

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 and the Republic of Korea War Service Medal.