The four main causes of The Civil War were Slavery, Sectionalism, States Rights, and Tariffs. The North and The South had a conflict because The North and the abolitionists, didn't want slavery to continue and The South wanted slavery to continue. Both Sides thought they were better and chose themselves over the other . The South said they had the right to secede from the united states. So they did. The North made Tariffs because they wanted The south to buy from them rather than England.