Sergeant Hilburn was a member of Company B, 1st Battalion, 38th Infantry Regiment, 2nd Infantry Division. He was listed as Missing in Action while fighting the enemy in North Korea on 1 December 1950 and returned to duty on 3 December 1950. He was listed as Missing in Action in South Korea on 12 February 1951 and presumed dead on 31 December 1953. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Hilburn was awarded the Purple Heart with Oak Leaf Cluster, the Combat Infantryman's 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.