Idea
The civil war is a conflict that opposed north and south of the us (mainly at the east).
During the 1860s northern states of the us had a growing industry that made them independent of slaves. While the South, which economy was primarily agricultural, was relying heavily on slaves. This created a tension between then northern states and southern states which after some years came to a cession of southern states from the Union. Then it transformed into a war, Lincoln claiming first that it was to re-establish the union, then that it was for slave emancipation, to prevent European countries interference. (Europe was then importing cotton from the US and supportive of the southern states)