Yale historian David Blight tackles the old historiographical debate over the Civil War's cause, weighing the nineteenth-century case that the conflict was an avoidable, needless war against the argument that it was an irrepressible conflict rooted in slavery. Delivered as Class 13 of Yale's 2024 DeVane Lecture Series, Can It Happen Here Again? Yale, Slavery, and Legacies, the lecture traces how generations of historians have assigned blame, from states' rights framings favored by Lost Cause writers to the case that slavery itself was the war's engine. Blight situates the question within the course's larger argument that slavery and its legacies remain a central, unresolved thread in American political and constitutional life. Expect close attention to primary arguments from the period and to how later historians reshaped the debate for their own political moments.