Petition from citizens of Pennsylvania against slavery in the territories, February 7, 1854
When Congress debated the Kansas-Nebraska bill, leading citizens of Chester County, Pennsylvania, petitioned against the repeal of the Missouri Compromise. As abolitionists, they opposed any change that would extend slavery. One signer, William Darlington, served in Congress during passage of the Missouri Compromise in 1820.
Records of the U.S. House of Representatives, National Archives and Records Administration
The issue of slavery became more volatile as the nation expanded to western territories during the 19th century. In 1854 Congress passed the Kansas-Nebraska Act, repealing the Missouri Compromise, which had set a boundary between free and slave territories. The act supported popular sovereignty by allowing residents of new territories to decide whether to permit or prohibit slavery. The result was bloody conflict as pro- and anti-slavery forces flocked to Kansas to determine its future.