For others' sake, I double-checked: 2.59 million served, of which 648,500 were draftees. Right at 25%
Is there a study of soldiers who enlisted but only because their draft number was low? There were substantial benefits to enlisting, because you could choose your branch of service.
It would be more interesting to see those numbers broken down by frontline service. What percentage of the guys actually dying in the jungle were drafted?
Should break that down by people who had enlisted before hostilities began. Material difference enlisting during peace time vs when there is an active theater of war.