Sergeant Sheffield was a member of Company A, 1st Battalion, 7th Cavalry Regiment, 1st Cavalry Division. He was seriously wounded by the enemy in South Korea on 12 August 1950 and returned to duty later that day. He was Killed in Action while fighting the enemy in South Korea on 11 September 1950.

Sheffield 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 and the Republic of Korea War Service Medal.