What was the purpose of the civil war

The Civil War is one of the most important events in American history. The purpose was not just about ending slavery. There were two parts of the United States that had two separate reasons for the war. The Southern part indeed focused on slavery but some argue that they were also focused on the states' rights and its independence. On the other hand, the Northern part was also fighting slavery but they were focused more in preserving the different unions of its states.