The most contributing factor to the coming of the Civil War was slavery, an economic issue to the South and a moral issue to the North. Slavery was the driving force for the Southern slave states to leave the Union. The Civil War was ultimately caused by the secession of the Southern states from the Union. Slavery had caused a great division in our country by the 1850's. The abolitionists of the North proclaimed that slavery was immoral and wrong, and the Southern "fire eaters" were dependent upon slave labor to run its large plantations where the "cash crop" of the South, cotton, was grown. The South, being predominantly agricultural, needed these s