When I graduated from HS in 1975 I was only required to have one year of American History and one semester of Civics. Because they were required for graduation they were taught at a very low level so everyone could pass. There was no AP options or follow on electives that I remember. Our school was generally well regarded in an average to above average suburban area, not some inner city school. Our other academic classes prepared us well so it shows the low priority the social studies had.