Yale historian David Blight covers the final years before the Civil War, tracing how John Brown's 1859 raid on Harpers Ferry hardened sectional divisions and turned Brown into a martyr for abolitionists and a terrorist symbol for the South. The lecture moves through the fractured 1860 election, in which a divided Democratic Party allowed Abraham Lincoln to win with a purely northern coalition, and then follows the secession crisis that unfolded in the following months as southern states began leaving the Union. Blight situates these events within his DeVane Lecture Series course on slavery's legacies in American history, part of Yale's Can It Happen Here Again project. This is lecture twelve, delivered in his familiar narrative style, weaving political detail with the moral stakes of a nation splitting apart over slavery.