That hasn't been my experience in American schools, nor anyone that I've discussed the topic with. In my final year of High School education I had some freedom

That hasn't been my experience in American schools, nor anyone that I've discussed the topic with. In my final year of High School education I had some freedom, but it was along the lines of, "You have access to advanced Biology, Physics, and English. Choose two." (It was more complicated than this, simplified for example's sake) For the rest of high school I had one elective course and the rest was more rigid. I was able to choose which foreign language I would like to study and I could choose a particular artistic pursuit. Everything else was thoroughly constructed and regimented. Arts, Humanities, Sciences, Mathematics, Language were required each year. Even when I went to college, the first two semesters required the same mix of curriculum before I was able to specialize.