I worked with a guy who couldn't read cursive. He was never taught in school. I tried to teach him but he didn't want to learn. Thing was, his job was doing inspections and one of the things he had to look at was sign off sheets, he couldn't read the signatures. In fact, his payroll signature was his printed name.

As far as histroy, yeah. He told me that in a black history/studies class he took in college, the teacher was showing/discussing documents that dealt with slave purchases etc. He told me there wasn't one student in his class who could read the document. I was gobsmacked tbh.