I taught high school for 30 years, and always taught about the genocide (I used the word) of the Native Americans and US Imperialism generally. I taught about the Filipino "Insurrection", and the crushing of the labor movement with US troops and local "militias".
I taught about Vietnam as a clusterfuck and a war crime. (Having been a participant in the Southeast Asia War Games gave me some perspective.)
I taught about real slavery, and the civil rights movement and the women's movement.
I could go on, but you get the drift.
One problem with all that. Not enough time in the curriculum...in the year...in the day... to cover both regular history and government and the real stuff. About 75 hours in a semester. Sounds like a lot, but my Middle-East Peace Conference - role-playing - took 4 hours alone. The debate about dropping the bomb on Japan took about the same. The kids had the usual Pablum textbooks, and I spiced their reading up with Howard Zinn and some primary sources. This... before the Internet.
We need enough time in the schools to tell the WHOLE story. Not only critical race theory... we need time to teach critical HISTORY theory. And critical GOVERNMENT history. And critical everything.... The way things really ARE.
Some districts, like ours, had an academic freedom clause in the teachers' contracts, and "critical thinking skills" were in the guiding documents of the district.
Was it paradise..? Not hardly, but it was a district of well-educated, upper-middle-class folks who wanted the best.... even if there were warts.
The kids in the red states...Texas... and the inner cities.. and many other areas, don't get half of that. They get bullshit... regurgitated bullshit at that.
The Republican drive to kill public education is working. We have to turn it around.
Our real need for infrastructure is in education, and the Republicans are working as hard as they can against it.
