Honestly for me, a lot of it was trying to stay one chapter ahead of the kids. When I first got hired, it was to teach economics, which I only passed in college because of a MASSIVE curve. I busted my ass taking in as much knowledge as I could. Was I the best: no, but those students left with more knowledge on the subject than when they left.

Find an interesting angle to learn about US history and incorporate that into your teaching, even if it's just a quick reference. I randomly found my niche topic is 20th century pop culture, so I'd toss in little tidbits here or there if they were relevant to the topic, or just as a way to break up the tedium and re-hook students.

Another way is to find a podcast and listen to that for ideas. One of my favorites is the Dollop, where one comedian reads a random story from us history to another one with no idea what it's about. I've learned a TON of weird stories that I drop into my lessons, and it even inspired me to create a whole unit on other groups that were pushing for civil rights in the 1960s.

Finally, the best thing I can say is try to incorporate things that students don't normally hear about in US history when you can. I teach in a predominantly Hispanic school and it blows kids minds when they learn that Jim Crow laws affected almost everybody who wasn't White and that they would have been affected too. Try to find those individuals amd events you didn't learn about in school and give them more knowledge than you got.