By the summer of 1856, the debate over whether or not the territory of Kansas would become a free or slave state erupted into widespread violence, including John Brown’s killing of proslavery settlers in the Pottawatomie Massacre and the sacking of the Free-State stronghold of Lawrence, Kansas. Pro- and antislavery factions gathered men into paramilitary units and sought out their opponents across the territory and in neighboring Missouri. Against this backdrop, proslavery forces targeted known abolitionist strongholds in hopes of driving their residents from the territory.