What does "Bleeding Kansas", John Brown's Raid on Harpers Ferry, the Dred Scott Decision, and Uncle Tom's Cabin, all have in common

Bleeding Kansas and John Brown's Raid, were violent abolitionist movements, prior to the beginning of the Civil war in the 1860's, Uncle Tom's cabin was a novel written about a slave and his different owners and their personalities didnt detail the full cruelty of slavery, the Dred Scott decision was a slave going before the Supreme Court and asking for his freedom because of the ruling of the Missouri Compromise, yet was denied his freedom because African Americans didn't have the same freedoms or opportunities as others did. I would say that there are either all responses to the abolitionist movement prior to the Civil War

They showed the power of the federal government.