That's just not true. The Haymarket Riot is widely taught in history classes. I don't think there's a single history class that covers the 20th century and fails to mention the Great Depression and the New Deal. They might not spend a lot of time on things like the Bonus Army, but you can't really cover the Great Depression without mentioning rebellions and unrest.

It's true that they like to talk a lot more about the genius of Henry Ford and give him credit for the 5 day work week, and not mention all the labour movements and strikes that led to the 8 hour day and 5 day week. But, it's more a matter of what's emphasized rather than outright censorship.

Besides, the whole founding of the US is framed as a rebellion against authority. They barely even mention that the founding fathers were almost all extremely rich nepo babies. The founding story of the US could be taught as a bunch of rich white men who deserved to lead because of their prowess as capitalists taking power from a distant king who was demanding a bailout due to his financial mismanagement. That would probably even be closer to the truth. But, it's framed as a bunch of plucky men taking power back for the people from an autocrat.