States during the Civil War. Red is the south. Blue is the north. Tan is unknown territory.
The South and the North both had very different governments, and ideas. The southern states wanted more of the country's strength within the states. The northern states wanted a large federal government going on at this time. This caused huge rivalry going on between the two sides.
Now the south really wanted some certain rights going on here. They wanted Nullification Rights, so they could disregard any new law that was passed if it seemed unfair to them. Another right was Popular Sovereignty, which was where the states wanted to vote on major issues, and have the people vote for it. The last right they wanted was Secession Rights. This right was wanted, so any state could secede (or pull away from the U.S.A. if needed).
The Election and Secession
South Carolina's ordinance of secession
After Abe was elected, it made the South very scared that he would try, and put a stop to slavery. Because of this South Carolina pulled away from the U.S. and created a new country: The Confederacy of the United States. One by one the southern states pulled away from America.
This is what started to cause the war. It was 2 sides against each other, because southerners thought that Lincoln would get rid of slavery. They north wanted to get rid of slavery anyways, and that's why they seceded. Abe said that he wouldn't start the war. He said the south would have to fire first to start the war, and that's what happened.
Missouri Compromise
This was a compromise, obviously. This compromise allowed Missouri to become a slave state for the south, and Maine a free state for the north. It also stated that new states above Tennessee were free, and that the states under Tennessee would be slave to make it equal. Later the southern states found out that there was more land up north rather than the south making everything uneven. The south got mad and nullified the compromise.