Sectionalism

By the 1840s and 1850s, the northern and southern United States had developed different economic and social systems. They remained part of the same Union, but increasingly disagreed about whose interests the national government should protect. This growing sectionalism meant that regional loyalties could become stronger than loyalty to the country as a whole.

These differences encouraged sectionalism: loyalty to the interests of a region rather than the whole country. Nevertheless, economic differences alone do not fully explain the war. Slavery connected the arguments about wealth, freedom, westward expansion and political power.