The Kansas-Nebraska Act was also the result of westward expansion and north/south economic competition. The Kansas Territory was in the northern part of the Louisiana Territory so according to the Missouri Compromise it could not be a slave state. However, some politicians wanted to build a railroad across the country through Kansas and they needed to get southern support. Southerners, especially Jefferson Davis, wanted to build a transcontinental railroad on a southern route from New Orleans. The Kansas-Nebraska Act repealed the 36◦ 30’ line of the Missouri Compromise.
It allowed people in these territories to decide for themselves whether or not to allow slavery within their borders through ‘popular sovereignty.’ In order to affect that vote (not the way the concept of popular sovereignty was supposed to have worked!), northern abolitionists and southern slave owners temporarily moved into the Kansas Territory. Soon their fighting led people to call the area “Bleeding Kansas.” Some northern Whigs and northern Democrats who were appalled at the violence joined with the Free Soil Party (those opposed to the expansion of slavery) and the Liberty Party (abolitionists) to form a new political party: the Republicans