> Americans have little to no understanding of this history.

That's different than 'written out of'.

Americans know little about the Astor expeditions to the Pacific Northwest, the Fremont expeditions, Californian independence and statehood, or any number of other things.

American textbooks spend large amounts of text recounting the horrors of European colonialism in Africa, India, China, the Americas. Likewise, some recent textbooks do a half–decent job of discussing slavery and the genocide of indigenous Americans. There’s usually extended coverage of e.g. the Korean and Vietnam wars. By contrast, American colonial occupation of the Philippines is glossed over in a few pages, as a footnote to the Spanish–American war.

Do you think high school history textbooks should have detailed coverage of the Astor expedition, etc.? Or if not, what’s your point?