I think a lot of people think that free speech was a historic US value; in fact it was incredibly contested, and it took the civil rights movement in the 60s to really establish it as a vital part of US law (just as it took WW2 to push it to the forefront of universal human rights law). https://www.eff.org/deeplinks/2019/03/inextricable-link-between-modern-free-speech-law-and-civil-rights-movement