The Civil War began because of conflict between the Northern and Southern parts of the United States. The North had abolished slavery while the South still wanted it because it was their source of income. Slavery was a big cause of the Civil War. Another cause was the election of President Lincoln into office. He was considered a traitor to the Republicans of the South because Lincoln went against all their beliefs yet he was a Republican. Since the South had a grudge against Lincoln, they got out of the Union and formed a Confederacy. Lincoln didn't like this, he believed all states in the United States were "married" to one another and were not allowed to break away. Thence, the Civil War started.