How Did Sectionalism Lead to the American Civil War?

In the years prior to the American Civil War, a separate sense of cultural, political and economic identity developed and took hold between the North and the South that helped lead to the conflict. Sectionalism, which refers to loyalty to a section of a nation rather than to the nation as a whole, contributed to a Southern identity based not only on a distinctively different way of life, but on a geographically shared mistrust and apprehension towards the Northern way of life represented by the federal government and the election of United States President Abraham Lincoln. By the time of the election, the South had already developed its own sense of regional nationalism, based on a slave-labor agrarian economic system, that felt threatened by the anti-slavery stance of the heavily-industrialized North.