Not are taught, were taught.
In 1966, when I was in the 1st grade I saw through the Columbus "discovered" AmeriKKKa canard.
You haven't looked at a high school history or civics textbook published since 1970. I was a subsitute teacher in Oakland Public Schools from '85-'90, US history and civics was my fave to be sent to cover. In the Vietnam War section, the textbooks mentioned the My Lai massacre. Other events like Wobblies being killed, lynchings, the battles over Contra aid, were in the texts.
The teaching of history has changed alot since the triumphalist, Nationalist narratives of the 50's, due to the victories of radicals and left-liberals in the 60's and 70's, which remain in the popular culture (even if under savage attack, but, multiculturalism is here to stay) and the historical profession (AHA has since the 70's elected repeatedly, neo-marxists for Pres.) is left-leaning.
See the Peter Novick classic on US historiography, "This Noble Dream." Careful though, CB, in the extensively annotated footnotes, Novick relates how he (and many, many others, prominent in the profession) was a Trotskyist in the 50's. Damn, reactionary, red-baiter, anti-Sovieteer.
And "red-baiter, " btw, awfully slippery term. The UCLA Daily Bruin, announcing Angela Davis talk in the 80's said she was a Communist. Oh, the howls of outrage flowed in to the editor.
-- Michael Pugliese