Antebellum Sectional Crisis

Between the Mexican–American War and secession, disputes over whether slavery could expand into western territories repeatedly destabilised national politics. Compromises, fugitive-slave enforcement, abolitionist resistance and violence in Kansas deepened mistrust between North and South.

Industrial and commercial differences mattered, but slavery remained the central sectional issue. Political parties fractured as Southern slaveholders defended their power and many Northerners resisted its extension, even when they did not support racial equality.