From atleast the time of the big state institutions for people labeled "feeble minded," people with intellectual disabilities have done care work to support other people with disabilities.

From Roland Johnson:

"I remember the first ward that I worked on. I was about seventeen or eighteen. It was snowing; they had a few staff persons on M-1, but they didn't have enough staff persons to cover that ward. (cont.)

"When it was cold and snow they didn't have staff -- one of the staff had to work overtime; they couldn't get another staff to change shift. And we had to sleep there when there was no staff. (cont.)

"I remember he said that, "Roland is my workboy this week." There'd be eight or seven people worked on a ward, but we never got paid for it. The staff person just watched, just watched, the head staff person. Patients used to do all the work. (cont.)

"They helped to change the babies. So we had to bathe them and wash them and brush their teeth and stuff like that. Now these are people that could not able to take care of themselves. (cont.)