Graduate, U.S. Military Academy, Class of 1946.

Captain Castle was a member of the 504th Airborne Infantry Regiment, 82nd Airborne Division at Fort Bragg, North Carolina. He had served with the 5th Cavalry Regiment, 1st Cavalry Division in Korea from 1947 to 1950. He died at Fort Bragg, North Carolina on 23 January 1951 as a result of a routine training aircraft accident.

Castle 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.