Most of those who faced the draft and fought in Vietnam were born 1943-1953 (more from 1943-45 than from 1951-53). The earliest boomers, 1946-50, were the peak. 1948 was the birth year that had the most men in Vietnam and the most casualties.
I was born in 1953. (Monday is my birthday, btw, turning 58.) I had a draft number, #2, but I also had a deferment, since I was preparing for church ministry. And very few from my birth year, 1953, actually went to Vietnam. The war was winding down by that point in the early '70s.
The Vietnam War goes back to the early days of JFK, which means that older men ( those born in the late '30s and early '40s ) were there, "the advisers", who weren't "advising" anyone, but fighting, long before the antiwar movement enlisted the younger morons into that fray. That group, BTW, was led by stinking Commies, who had been at this crapola since WW II!
An early HAPPY BIRTHDAY !