The US is probably the one country worse than us for this - and they only have a few hundred years of history as well.
The Tulsa massacre is one that's come into focus recently - up to 200 black people killed by a white mob assisted by the national guard and the richest black community in the USA, nicknamed Black Wall Street, burned to the ground. The worst racial violence since the abolition of slavery.
They don't even teach it in Oklahoma - and the only records are from the KKK who made postcards as souvenirs because the government tried to airbrush it.
https://en.wikipedia.org/wiki/Tulsa_race_massacre
It's only really come back into public consciousness since HBO's The Watchmen featured it.
Then there's the Native American genocide, Vietnam and even a "both sides" approach to the civil war.
But then again we're talking about a country where people are still, in 2020, trying to ban To Kill a Mockingbird in school libraries...