Those texts were a standard part of grade school social studies when I was young, and my children read all in the course of a typical public education long before graduating.
They might be part of the curriculum, but apparently ~half the country doesn't know what we just celebrated[0], so I somehow doubt they actually did their reading. It's pretty easy to pass or even do well in classes without really engaging with the material at all, even at the university level. Like I got an A in a philosophy course by just reading the professor's notes on exam morning and spitting them back out on an essay. I've still never gone back and actually read Grotius.
Right but that's just it: it's barely the upper half (over 40% of young people now get a degree apparently[0]), and the age breakdown indicates that 40% is also apparently the proportion of 18-29s that know we declared independence 250 years ago. So assuming continuity and rough correspondence of the two distributions, that's approximately the level of knowledge at the threshold of degree holders now.
Actually the census data says ~43% get a degree and the article says 39% of 18-29s know what we celebrated, so presumably at least 4% (~9% of degree holders) are able to get a degree and don't know.
If this is our bottom end, I get the sense that even above-average students (even of liberal arts) aren't reading Montesquieu or whatever image people try to evoke about highly educated societies.
[0] https://www.npr.org/2026/07/03/nx-s1-5881451/cato-institute-...