Corporal Walker was a member of Headquarters Company, 2nd Battalion, 29th Infantry Regimental Combat Team. He was listed as Missing in Action while fighting the enemy near Chinju, South Korea on 31 July 1950. He was presumed dead on 31 December 1953. His remains recovered on 4 June 1987 and was identified on 26 October 1987. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Walker 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.