So ive been taking a US civil war class and we were on the ante-bellum years for a quite some time and we learned about the great sectionalism that literally split the two hemispheres of the Union. What exactly caused the secession that took place, literally, months after lincoln was elected?
A very short answer: most of the divide came from political and economic debates over slavery. The states in the South that were dependent on slavery believed that attempts to ban slavery violated their rights to self-determination and was part of a plot by the industry of the North to cripple them. Lincoln wasn't abolitionist but he wasn't promising to protect slavery and that was the last straw for many