I went to public school in PA from the mid 80’s through the late 90’s.
But as I posted earlier, states( and in some very few instances, areas within some states) have control of what kids read or don't read in public schools and times change.
It probably is no longer true; however, there was a time when ALL schools, private, public, specialized, and parochial, in New York State had to follow the state's mandated syllabus for each grade, K-12. That was due to the Regents tests, I surmise, which every student had to take in high school.