I remember that year too. My husband had just gone with his company from Fort Campbell to his first tour in Vietnam. His second tour was in 1971 and he volunteered for both tours
Oddly, a lot of folks don’t know that there were a LOT of folks who volunteered to go to VN. Just cause you got drafted was not a guarantee you were headed there. I went in the Navy because my dad was a career officer. He actually swore me in. That was cool.