The government targeted disabled people from some of the poorest communities in the country, who McNamara referred to as, "the subterranean poor."

Many of those drafted were illiterate, they had to be taught to tie their shoes, and they didn't know things like who the president was, even as they were being sent to kill and die on his orders for an imperialist war, for reasons they could not understand.

A book called McNamera's Folly records some stories of those recruited in the program. One thought a nickel was worth more than a dime, because it was bigger. One of them failed to attend training and was sentenced to four years of labor in prison, and the sergeant asked if anyone "wanted to join them in the stockade." Another conscript didn't know what the word "stockade" meant and thought it meant going home, so he said yes - he received the same sentence.

If you can believe it, this was actually sold to the public as a "progressive" program, as part of Johnson's "War on Poverty." The claim was that this would be a way to help the conscripts learn useful skills. in reality, a study by the DoD itself found:

Comparisons between Project 100,000 participants and their non-veteran peers showed that, in terms of employment status, educational achievement, and income, non-veterans appeared better off. Veterans were more likely to be unemployed and to have a significantly lower level of education. Income differences ranged from $5,000 [to] $7,000 in favor of non-veterans. Veterans were more likely to have been divorced.

Obviously.