Missouri Compromise: The Missouri Compromise was an agreement that aimed to maintain balance between free states and slave states by admitting Missouri as a slave state while Maine entered as a free state. It also established a line (36ยฐ30' parallel) where future territories north of it would be free while those south could choose slavery.
Popular Sovereignty: Popular sovereignty is the idea that residents of a territory should vote to decide their own stance on issues such as slavery. It played a central role in determining whether Kansas would become a free or slave state during Bleeding Kansas.
Border Ruffians: Border Ruffians were pro-slavery individuals from neighboring Missouri who crossed into Kansas to influence elections and intimidate abolitionists. They contributed to violence and unrest during Bleeding Kansas.