Au contraire my friend, militia from Sheffield were called to Nottingham to disperse election riots as late as the 1880's. I doubt that that was a one off either, it's just the one I'm aware of due to the history of a building I once lived in. No one was killed and since the riot was party v party it doesn't fit the Marxist narrative of the people v evil and undemocratic government so it doesn't get any publicity.I naively assumed everyone knew about Peterloo. Especially in the Army, since it hasn't been deployed in that way since on this side of the Irish Sea.
On the general subject, every generation likes to imagine they discovered everything, sex, drinking, new music, history, etc. when in reality they just work things round in cycles.