The Civil War happened 8 years after Brooks' cowardly assault on an unarmed man. And the first shots were fired by the "winning" side of Brooks' embarrassing violence.
Brooks and Sumner's argument was over the phenomenon that led to the Civil War.
Interesting research in that book though.
Brooks’ cowardly assault on an unarmed man.
If... he had believed Sumner to be a gentleman, he might have challenged him to a duel.
Instead, he chose a light cane of the type used to discipline unruly dogs. Sumner got off light and he kept his mouth shut after that.
There is to this day a price to pay for insults no matter the pay grade. Horns still hook.