Our high school history and civics classes were strictly controlled, whether we (as students) realized it or not. Our teachers wanted to teach us these things in many cases, but they were prevented by administrators and School Board review.
Any time a "liberal-thinking" teacher mentioned political history or racial sensitivity, and a student went home and told his parents what he/she learned in school - it was usually parents who went on a rampage. Angry parents would alert the School Board, complain to the principal, and get THAT teacher sanctioned or fired.
We shouldn't kid ourselves, and we shouldn't blame the teachers. In many cases our teachers had their hands tied, even as far back as the 1950's and 60's. I can only speak of public and Catholic diocese schools, I had no experience in private schools, but I'd have difficulty believing they were any more liberal.
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