The Civil War
The coexistence of a slave-owning South with an increasingly anti-slavery North made conflict likely, if not inevitable. Lincoln did not propose federal laws against slavery where it already existed, but he had, in his 1858 House Divided Speech, expressed a desire to "arrest the further spread of it, and place it where the public mind shall rest in the belief that it is in the course of ultimate extinction." Much of the political battle in the 1850s focused on the expansion of slavery into the newly created territories. All of the organized territories were likely to become free-soil states, which increased the Southern movement toward secession. Both North and South assumed that if slavery could not expand it would wither and die.
Southern fears of losing control of the federal government to antislavery forces, and Northern resentment of the influence that the Slave Power already wielded in government, brought the crisis to a head in the late 1850s. Sectional disagreements over the morality of slavery, the scope of democracy and the economic merits of free labor vs. slave plantations caused the Whig and "Know-Nothing" parties to collapse, and new ones to arise (the Free Soil Party in 1848, the Republicans in 1854, the Constitutional Union in 1860). In 1860, the last remaining national political party, the Democratic Party, split along sectional lines.
Both North and South were influenced by the ideas of Thomas Jefferson. Southerners emphasized, in connection with slavery, the states' rights ideas mentioned in Jefferson's Kentucky Resolutions. Northerners ranging from the abolitionist William Lloyd Garrison to the moderate Republican leader Abraham Lincoln emphasized Jefferson's declaration that all men are created equal. Lincoln mentioned this proposition in his Gettysburg Address.
Confederate Vice President Alexander Stephens said that slavery was the chief cause of secession in his Cornerstone Speech shortly before the war. After Confederate defeat, Stephens became one of the most ardent defenders of the Lost Cause. There was a striking contras between Stephens' post-war states' rights assertion that slavery did not cause secession and his pre-war Cornerstone Speech. Confederate President Jefferson Davis also switched from saying the war was caused by slavery to saying that states' rights was the cause. While Southerners often used states' rights arguments to defend slavery, sometimes roles were reversed, as when Southerners demanded national laws to defend their interests with the Gag Rule and the Fugitive Slave Law of 1850. On these issues, it was Northerners who wanted to defend the rights of their states.
Almost all of the inter-regional crises involved slavery, starting with debates on the three-fifths clause and a twenty year extension of the African slave trade in the Constitutional Convention of 1787. There was controversy over adding the slave state of Missouri to the Union that led to the Missouri Compromise of 1820, the Nullification Crisis over the Tariff of 1828 (although the tariff was low after 1846, and even the tariff issue was related to slavery), the gag rule that prevented discussion in Congress of petitions for ending slavery from 1835â€“1844, the acquisition of Texas as a slave state in 1845 and Manifest Destiny as an argument for gaining new territories where slavery would become an issue after the Mexicanâ€“American War (1846â€“1848), which resulted in the Compromise of 1850. The Wilmot Proviso was an attempt by Northern politicians to exclude slavery from the territories conquered from Mexico. The extremely popular antislavery novel Uncle Tomâ€™s Cabin (1852) by Harriet Beecher Stowe greatly increased Northern opposition to the Fugitive Slave Law of 1850.
The 1854 Ostend Manifesto was an unsuccessful Southern attempt to annex Cuba as a slave state. The Second Party System broke down after passage of the Kansas-Nebraska Act in 1854, which replaced the Missouri Compromise ban on slavery with popular sovereignty, allowing the people of a territory to vote for or against slavery. The Bleeding Kansas controversy over the status of slavery in the Kansas Territory included massive vote fraud perpetrated by Missouri pro-slavery Border Ruffians. Vote fraud led pro-South Presidents Franklin Pierce and James Buchanan to make attempts (including support for the pro-slavery Lecompton Constitution) to admit Kansas as a slave state. Violence over the status of slavery in Kansas erupted with the Wakarusa War, the Sacking of Lawrence, the caning of Republican Charles Sumner by the Southerner Preston Brooks, the Pottawatomie Massacre, the Battle of Black Jack, the Battle of Osawatomie and the Marais des Cygnes massacre. The 1857 Supreme Court Dred Scott decision allowed slavery in the territories even where the majority opposed slavery, including Kansas. The Lincoln-Douglas debates of 1858 included Northern Democratic leader Stephen A. Douglas' Freeport Doctrine. This doctrine was an argument for thwarting the Dred Scott decision which, along with Douglas' defeat of the Lecompton Constitution, divided the Democratic Party between North and South. Northern abolitionist John Brown's raid at Harpers Ferry Armory was an attempt to incite slave insurrections in 1859. The North-South split in the Democratic Party in 1860 due to the Southern demand for a slave code for the territories completed polarization of the nation between North and South.
Other factors include sectionalism (caused by the growth of slavery in the lower South while slavery was gradually phased out in Northern states) and economic differences between North and South, although most modern historians disagree with the extreme economic determinism of historian Charles Beard and argue that Northern and Southern economies were largely complementary. There was the polarizing effect of slavery that split the largest religious denominations (the Methodist, Baptist and Presbyterian churches) and controversy caused by the worst cruelties of slavery (whippings, mutilations and families split apart). The fact that seven immigrants out of eight settled in the North, plus the fact that twice as many whites left the South for the North as vice versa, contributed to the South's defensive-aggressive political behavior.
The election of Lincoln in 1860 was the final trigger for secession. Efforts at compromise, including the "Corwin Amendment" and the "Crittenden Compromise", failed.
Southern leaders feared that Lincoln would stop the expansion of slavery and put it on a course toward extinction. The slave states, which had already become a minority in the House of Representatives, were now facing a future as a perpetual minority in the Senate and Electoral College against an increasingly powerful North.