You may laugh when I say this, but it just might be your constitutional right to tell a group of unsuspecting tourists a whole load of bull if you feel like it. Even if you're getting paid to give them a tour. George Washington slept here. No, wait a minute, I think he actually slept over there. Or was it someplace else altogether?
The issue at hand is whether the city of Charleston, South Carolina can compel tour guides to take a class and pass a test before they begin giving tours. The free speech question arises because in a city as old as Charleston, there is a lot of history to talk about, and a lot of that history is deeply entwined in the politics not just of its time, but also of our time. Anyone telling those stories undoubtedly chooses which stories to tell and also offers some opinions about the events contained in them. Regulating that speech therefore can be construed as regulating the content of that speech, a scenario that immediately raises First Amendment questions. The protections would also extend to statements that are inaccurate. You mean, Benjamin Franklin wasn't born in Albuquerque?!
The task of untangling this thorny conundrum has fallen to a federal judge in Charleston and judicial watchers are trying to read the tea leaves on how this is going to play out. The judge's refusal to dismiss the case has given hope to those who see this as a constitutional issue. Still, his denial of a preliminary injunction means that the law is still in effect.
So, the next time you're looking at some old stone wall, and someone is trying to tell you that Muhammad Ali once leaned against it, you might check with Google too.
All of this, and more, can be found in this Bloomberg article:
http://www.bloomberg.com/view/articles/2016-07-12/free-speech-protects-tour-guides-even-the-ignorant-ones