Private First Class Trueblood was a member of Company L, 3rd Battalion, 7th Cavalry Regiment, 1st Cavalry Division. He was seriously wounded by the enemy in South Korea on 3 September 1950 and returned to duty on 10 September 1950. He was Killed in Action while fighting the enemy in South Korea on 13 September 1950.

Trueblood was awarded the Purple Heart with Oak Leaf Cluster, 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.