You might be interested in James Loewen's book Lies Across America: What Our Historic Sites Get Wrong (he's also the author of the better-known Lies My Teacher Told Me). Although I think/hope some of the historic sites and markers whose flaws he reveals have been changed by now, it's a trenchant look at the trivial and very NON trivial omissions, emphases, and flat-out dishonesty of U.S. historic tourist attractions.

Again, I'm not sure if/how this has changed since 1999, but on the other hand that preserves this sub's 20 year rule, so. :)

The most striking thing to me was the systematic erasure of slavery among historic sites. Sure, there are plaques marking known Underground Railroad sites or whatnot. But Loewen describes plantation site after plantation site whose grand tours not only don't include anything remotely resembling slave quarters, but talk about "servants" and "domestic help" and all other ways to deliberately obscure that this grand southern way of life could not have existed without the bitter enslavement of people.

The other big trend I remember from the book is the overall portrayal of American Indians in Western Plains historic sites and markers. Particularly, historic markers where various Indian nations are said to have massacred wagon train Oregon Trail traversers...massacres that did not, in fact, happen. The sum effect of these, argues Loewen, pushes the manifest destiny/white right/"Cowboys & Indians" narrative that justifies ongoing legal and spatial oppression of Indians in the U.S.