Yale historian David Blight delivers the ninth lecture in his DeVane Lecture Series course on slavery and its legacies in American life. Here he turns to the competing economic and ideological systems that took shape in the North and South before the Civil War, tracing how each region built a self-justifying worldview around its labor system. Blight lays out how Southern planters defended slavery as a positive good and the foundation of a stable social order, while Northern industrial and free-labor ideology framed wage work and capitalism as morally superior. The lecture connects these worldviews to the broader argument of the course, that slavery was not a regional aberration but a structuring force in national politics and economy. Drawing on his research into Yale's own ties to slavery, Blight situates the sectional divide within the larger question the course keeps returning to: what conditions allow a pluralistic constitutional democracy to survive its own contradictions.