In doing some research on the Vietnam War, I've read that 2/3 of the soldiers in Vietnam volunteered. Many people believe otherwise. I've found that most nuggets of information are based off of a particular speech that I cannot seem to dig up: Speech by Lt. Gen. Barry R. McCaffrey, (reproduced in the Pentagram, June 4, 1993) assistant to the Chairman of the Joint Chiefs of Staff, to Vietnam veterans and visitors gathered at "The Wall", Memorial Day 1993.
I've found the Westmoreland source, but am coming up dry on the McCaffrey. Is there anyone here that can point me to a primary or secondary sources on this? My research project hinges on the number of volunteers versus drafted in Vietnam in comparison to other wars.
This is the furthest I've gotten and it's not enough. "2/3 of the men who served in Vietnam were volunteers. 2/3 of the men who served in World War II were drafted. [Westmoreland] Approximately 70% of those killed were volunteers. [McCaffrey] Many men volunteered for the draft so even some of the draftees were actually volunteers."
I don't know how much this will help you, but this primer direct from the Selective Service .gov website states:
The U.S. presence in Vietnam expanded slowly from a handful of "advisors" in the 1950s and early 1960s, to an intensified conflict fought by a largecommitment of American troops. Of the 8.8 million individuals who served in the Armed Services during the Vietnam era, less than 1.8 million entered through the draft.
Regarding WW2:
In fact, nearly one million men were drafted in 1941, before the bombing of Pearl Harbor, and about two-thirds of the manpower for the entire war was provided by the draft.
The specific numbers are given as well:
as /u/flynavy88 mentioned, the Selective Service website gives numbers of draftees for the conflicts in question:
WWI: 1,666,867
WWII: 10,021,279
Vietnam: 1,766,910.
In WWI, about 4.5 million served. In WWII, slightly over 16 million served. That jives with your numbers.
Now, it gets a bit trickier when we talk about what -percentage- of Vietnam warfighters were drafted. During the conflict (5 August 1964-28 March 1973) 9,087,000 individuals served on active duty. That said, 2,594,000 served in Vietnam, with about half of those either seeing combat or providing close support.
Given where draftees went, this explains the proportionally low percentage of draftees and their correspondingly high mortality rate. It also explains how you could get wildly different answers.
HTH!