History books tend to be extremely biased
When I read this I thought “yes they are, but aren't teachers biased as well?”, but then I read the following two bullets and I realized you might have had in mind a waaaaaay higher level of bias than I had.
Some of the books have a lot of material on how "godly" the founding fathers were, how america is like the fulfillment of prophecies, etc. I have no idea how bad normal history books are, though. For my folks, the opposite meme sort of won ("christians are a tiny, persecuted minority in this country"). Some people manage to believe both memes at the same time, but not my parents.
If it's worth saying, but not worth its own post, even in Discussion, it goes here.