The scariest part is NOBODY taught this in school--not Republicans or Democrats. This wasn't a partisan effort to hide the past by either political party; they simply didn't teach it because it wasn't necessary to pass the tests and/or graduate.
I only learned about this because I stumbled on a word I didn't understand in context: i thought bundt was only used to identify a kind of cake. And when I looked up where the use of that word came from, that's when I learned. I can plainly tell you there are too many people who simply give up and don't look into learning more about the things that they don't understand.
That's why this was allowed to happen again.