On December 20, 1860, South Carolinians voted to abandon the Union and sparked the deadliest war in American history. Led by a proslavery movement that viewed Abraham Lincoln’s place at the helm of the federal government as a real and present danger to the security of the South's system of slavery, southerners—both slaveholders and nonslaveholders—willingly risked civil war by seceding from the United States. Rather than staying within the fold of the Union and awaiting the new president’s conduct regarding slavery in the territories and in the slave states, secessionists took bold action to change their destiny. By acting on their expectations of what the new president would do instead of waiting for his actual policy initiatives, they wagered on the possibility of a different future. This dissertation contends that the southern fear of slave insurrection, which was influenced by the Haitian Revolution, and the belief that northern antislavery forces would use violent uprising to end southern slavery shaped the planter ethos over the arc of the antebellum period, affecting national politics. Furthermore, this project explains why secessionists viewed Abraham Lincoln's support of the Wilmot Proviso as a valid reason for disunion.