God bless the internet. Here's a little 13 minute instructional film from 1947 for teachers about how to maintain discipline in a classroom. Watching it, you notice some things that are clearly from another place and time, as well as casual sexism and an all-white batch of students.
But after you get past the old-timey yuks, it's notable that some of the message still holds up. In particular, the notion that respect is a better classroom glue than fear, and that treating students like low-life scum doesn't work nearly as well as treating them like actual human beings. The relevance of that lesson is, sadly, driven home by the comments section, which mostly focuses on how the movie students are so much better than Kids These Days.
I would hope that if there's anything different in the country today, it's that it is once again okay to be kind, and that the solution to problems is not to simply overpower those who oppose you.
It is one of the basic lessons of human interaction that one can find playing out in a classroom--trying to wield your authority like a club creates more problems than it solves, and open contempt for the people you work with is a terrible approach for virtually anything at all, from running a classroom to leading a country. Today seems like a fine day to draw a breath, roll some tightness out of your shoulders, and embrace your kinder nature.