This article took me to places that I hadn’t considered. When I first broached the question, I had in my mind the North and South Poles, but when I sought to answer the difference between North and South, the U.S. Civil War wacked me over the head, making me feel that all you researchers out there were looking for the difference between the North and the South in the U.S. Civil War. So here is a Canadian giving you a simple answer to a rather complex and nuanced question.
When Abraham Lincoln took office in 1860, he had campaigned against expanding slavery beyond the states in which it already existed and made it clear that he was looking to do away with it altogether. This ruffled the feathers of 7 southern states, whose economies were built upon the backs of slaves, and caused them to declare their secession from the U.S. After the first battle at Fort Sumter, 4 more Southern states declared secession. The government naturally didn’t back this decision and asked for men to volunteer as soldiers to prevent the secession from happening. Interestingly, the Vatican recognized the independence of the Confederacy; not surprising given their long history of vicious oppression to dissenters but I digress.
In 1862, Abraham Lincoln announced the Emancipation Proclaimation, declaring all Confederate slaves that had escaped into the Union as free, even though the Union itself still had several states practicing slavery. When the Union won the war in 1865, nearly all of the slaves in the U.S. had been freed; close to 4 million.
The 11 Confederate States of America, led by Jefferson Davis included South Carolina, Mississippi, Florida, Alabama, Georgia, Louisiana, Texas (these were the original 7), Virginia, Arkansas, North Carolina and Tennessee. Missouri, Maryland, West Virginia and Kentucky has secessionist movements. They wrote their own constitution by taking much of the existing constitution, adding slavery causes and giving individual states more autonomy.