We were taught actual events and not what some feel how it should have been and should be
Looking back, I could not tell you the religious or sociopolitical beliefs of a single one of my teachers from 1st to 12th grade or in college. As you said, we were taught what occurred in history without any political or emotional spin attacked to it, and were encouraged to think critically about it. We were not graded or criticized for whatever conclusions we reached, but it is amazing how many of us reach the same conclusions. We were not taught that slavery was bad, but given the actual facts, we all reached that conclusion.
And we were given exercises to help us think critically.
I remember the teacher reading us a very short story about a boy from south America who moved to a small town where he rode his bicycle to school--in those days no cool high schoolers rode bicycles to school--he brought strange foods in his school lunches, he wore clothes different than all the other students. The teacher concluded with: would he fit in here?
Most of the class initially said no. He would be considered too weird, odd, different. One girl, daughter of Mexican immigrants, broke with the group. I think he would, she said. I don't think any of us would care what he brought for lunch--nobody held it against her that she brought homemade tortillas as often as bread in her lunches. We all had to agree with that.
And if he saw nobody was riding their bikes to school he probably wouldn't either. And we would accept his South American clothes or he would start wearing more American clothes.
The more I thought about that, I came to appreciate her reasoning and agreed. Not all my classmates did but they were less adamant in their positions. But it was a valuable lesson in critical thinking that everything isn't always absolute. At no time did the teacher even suggest what the correct conclusion should be.
I am pretty sure today's public school students do not get that kind of quality education.