Career
Thacker joined the Army from Salt Lake City, Utah in June 1969, and by March 31, 1971 was serving as a First Lieutenant in Battery A of 1st Battalion, 92nd Field Artillery Regiment. On that day, Thacker"s base in Kontum Province, Republic of Vietnam, was attacked by North Vietnamese Army forces. He assisted in the defense of the base and, when evacuation became necessary, he stayed behind to cover the retreat.
Trapped behind enemy lines, Thacker was able to evade capture until being rescued by friendly forces eight days later.