The University of Chicago has taken a stand for free speech and thought:
In 2015, faculty members issued the widely admired Report by the Committee on Freedom of Expression, a statement that later served as a model for policies adopted at Purdue, Princeton, Columbia, and other major universities.
Here is a link to the University of Chicago's aforementioned
Report by the Committee on Freedom of Expression, which is easily found online. It contains a number of interesting thoughts.
Does the US have laws the limit free speech when it is likely to cause harm eg. Provoking racial hatred etc?
Wikipedia has an entry on "
hate speech", with a section discussing
US Supreme Court case law. As a separate issue from legal matters, in a "court of public opinion", there is generally little tolerance for "hate speech"... that is to say, most people would tend to avoid it, and those engaging in it.