No, it’s covered. You might just be shocked to learn that children don’t really care about collective bargaining history anymore than the dates of important battles in WW2.
We covered the Triangle Shirtwaist fire, the muckrakers, and Roosevelt's war against trusts, but I don't ever recall hearing the name Eugene Debs, or say the Haymarket massacre.
There is a great deal of history where, yes, physical force & violence was used to break strikes. [0] <-- Just one example. [1] <-- another. [2][3] <-- more. The union labor movement is not at its most popular right now either. There'd be a lot more people rooting for the government right now.
I'd love to see them try.