"Although I have read some general histories of public education, I have never read a history specific to special education. I have a vague personal memory of a distant past when both, acceleration and retention, were more common, and I have talked to several people, slightly older than myself, who feel the same way."
I have first hand experience, albeit a sample of just one, that it was practically law in 1970. Mind you, I am speaking of Florida. In my last excursion to google books and Florida school superintendent reports from 1900 it was evident that Florida trailed New England by several decades in matters like compulsory education. It could very well be that Florida is atypical.
I do remember around the same time (1970's) through older extended family members that early graduation (finishing your required credits) was almost common up north. Florida didn't even have such a system when I reached high school.
In a parallel vein, I had a talk with my son a couple of weeks ago. He had gotten in trouble but the teacher had (according to him) mistaken his intent. He argued with the teacher which naturally made it worse. Of course I told him that arguing with a teacher will never have a good outcome and he should accept their authority like he does mine. He had that "I understand but not really look" so I explained further that school will probably be the most unjust place you will ever know but you will only aggravate the situation by arguing with teachers. Obviously, never allow them to do something bad to you but if you have a disagreement, for now, bring it to me when you get home. Of course, "bad" could mean many things.:)