Kansas

 

Historical Timeline
 1820 According to the Missouri Compromise of 1820, all territory north of 36 degrees 30 minutes latitude will be free of slavery.  
 1854 The Kansas-Nebraska act divides the Nebraska Territory in two, popular sovereignty is decided as the means to decide if if Kansas or Nebraska are free or slave states.  Soon proslavery and anti-slavery proponents come head-to-head in a fight over Kansas.
 1856 John Brown and six companions murder five pro-slavery men and boys at Pottawatomie Creek, Ks., part of a war of revenge that leaves 200 dead.
 1861 Kansas is admitted as a free state.