Essentially all history education in the US is heavily politicized except for WW2, the only thing Americans could agree on about the last 200 years is that Nazis were bad, and even that is now becoming 'controversial', with some schools like in Florida wanting to teach more about "both sides" of the holocaust. There's a reason my mom really loved the quote "Don't let school get in the way of your education."

The average knowledge of the things you mentioned would be "isn't Jackson the guy on the $20?" "Weren't gulags in Siberia or something? What even is a gulag exactly?" And "'Know Nothings'?? Yeah I literally 'know nothing' about that."

It's up to individuals and families to teach their kids actual history, and most parents both work and have little time to teach their kids anything that the schools don't teach them. And now I see kids leaning history from youtubers, it's a pretty depressing situation.