1820: The Missouri Compromise allowed Missouri into the Union as aslave state and Maine into the Union as a free state. Senator Henry Clay of Kentucky drafted a billthat maintained balance in Congress of slave vs. free state
1846: To prevent southerners from taking territory from Mexico in order to extend slavery, Representative David Wilmot of Pennsylvania proposed a bill known as the Wilmot Proviso. This bill was to outlaw slavery in any territory the US might acquire from the war with Mexico.
1850: Senator Henry Clay led the Congress in creating compromises on several issues during his long career including the Compromise of 1850. John C. Calhoun of South Carolina opposed the compromise while Massachusetts Senator Daniel Webster spoke in favor.
1858: Illinois Senator Stephen A. Douglas, sponsor of the Kansas-Nebraska Act, was challenged by Abraham Lincoln. Lincoln expressed the Northern fear that Southerners wanted to expand slavery to the entire nation. He set the stage for his argument using the Bible.
1859: John Brown, American abolitionist leader, wanted to inspire slaves to fight for their freedom. He and 18 of his followers captured the Harpers Ferry arsenal. He sent word to rally and arm local slaves but no slaves joined the fight. Brown was captured and hanged.
1860: Abraham Lincoln was elected as the 16th president of the United States. Many states where slave labor and cotton production were most common, withdrew from the Union.