southerners feared a slave rebellion like the one on haiti only a few decades earlier. they also feared that without slaves their economy would collapse completely. slavery had become a subject of vital interest to everyone in the united states. in 1859, the raid on the federal arsenal at harper's ferry, virginia by the abolitionist john brown shocked the south. had brown succeeded, he intended to arm slaves in the south with weapons to revolt against their masters. each new state admitted to the united states became a battle over whether it would be a free state or would allow slavery. extremists from all sides flocked to territories to promote their own cause. bleeding kansas became a worst case example where the competing views broke down into outright guerrilla warfare. political compromises were tried, such as the missouri compromise of 1820 and the compromise of 1850.