In January 1854, Illinois Senator Stephen A. Douglas introduced a bill to organize and open to white settlement the huge Nebraska territory west of Iowa and Missouri. Deeply committed to westward expansion for whites, he believed that his bill would encourage settlement and development there by removing the “Indian barrier” and establishing white governments. The area’s growth would also improve the chances of Congress choosing a route for the proposed Pacific railroad that would connect his home city of Chicago with California, thereby cementing his position as leader of the Democratic Party. Aware that the South would oppose his bill because the new territory lay above the Missouri Compromise line and would enter the union as a free state, Douglas suggested that the territory be split in two, implying that Kansas could come in as a slave state and Nebraska as a free one. Perhaps Douglas hoped that natural conditions would keep slavery out of the territory. Nevertheless, his advocacy of popular sovereignty, allowing the people of the territory to vote for or against slavery, effectively repealed the Missouri Compromise of 1820, which forbade slavery in the remainder of the Louisiana Purchase North of the 36° 30′ parallel. Popular sovereignty challenged the notion of whether Congress had the right to decide the slave question in a region that was still a territory. The South’s position was that only the states could do so.
President Franklin Pierce, who feared losing southern support, pressured northern Democrats to vote for the bill. Its passage set off storms of protest, angry speeches, and scathing editorials throughout the North against this “atrocious plot” to convert free territory into a “dreary region of despotism.” The Kansas-Nebraska Bill also put great strains on the party system as many northern Democrats, appalled at the repeal of the Missouri Compromise, bolted the party. It also split the Whig Party into northern and southern wings, ending its existence as a national party. In the summer and fall of 1854 Free Soilers, antislavery Democrats and Whigs, and the Know-Nothing (American) Party created a new antisouthern sectional Republican Party dedicated to keeping slavery out of the territories. This breakdown of national parties removed a moderating influence on radical northern abolitionists and southern extremists.
Finally, the bill’s passage triggered the conflict known as Bleeding Kansas, over whether Kansas would enter the union as a free or slave state. Proslavery “Missouri Ruffians” and antislavery Northerners rushed to the Kansas territory determined to influence the vote on statehood. Their struggle, characterized by rigged elections and savage fighting, led to a near civil war, including the sacking of Lawrence, Kansas, by slavery supporters and John Brown’s retaliation at Pottowatamie, Kansas, driving the two sides even further apart. While the turmoil in Kansas continued, in 1857 the Supreme Court, citing the Fifth Amendment’s Due Process Clause regarding private property, decided in the Dred Scott case that Congress could only protect, not ban, slavery in the territories, and the people of the territory could not prohibit it—only the states could do so. In one fell swoop, both the Missouri Compromise and the notion of popular sovereignty were rendered moot.
James McPherson, Battle Cry of Freedom: The Civil War Era (New York: Oxford University Press, 1998); Michael Morrison, Slavery and the American West: The Eclipse of Manifest Destiny and the Coming of the Civil War (Chapel Hill: University of North Carolina Press, 1995); Kenneth Stampp, America in 1857: A Nation on the Brink (New York: Oxford University Press, 1990); and Gerald Wolff, The Kansas-Nebraska Bill: Party, Section, and the Coming of the Civil War (New York: Revisionist Press, 1977).