Kansas-Nebraska actA guy wanted to build a choo-choo train across America, so he asked if Nebraska could be a slave state. It was decided by popular sovereignty that they would be free.
Raid on Harpers FerryAn Abolitionist named John Brown led an elaborate raid on a weapons arsenal in Harpers Ferry, in then Virginia. Soldiers led by Robert E. Lee subdued the abolitionists. the survivors were hung.