The issue of centralized power vs state sovereignty was nothing new in 1861. Just 30 years before the war, the nullification crisis came pretty close to resulting in an aggressive stance by the federal government. That was over tariffs that some powerful southerners believed put their regional economy at a distinct disadvantage to the northern region. These kinds of squabbles were ongoing from the time when the viability of the Articles of Confederation were being debated at the Constitutional Convention. A pressure cooker had been building for 60 years and the issue of slavery became the main point of contention during the 1850s. But it wasn’t noble or benevolent sentiment that made it the focus. It was the northern states industrial/manufacturing class strategy to balance the congressional power that had been dominated by the south for decades. They couldn’t compete with free labor as they paid wages to the European immigrant class. They were at a distinct disadvantage. The south controlled the economy. The only way to break that was to end the source of advantage. There were a lot of pre-cursers that were kindling to the inferno that occured in 61. The 3/5 compromise, The Missouri Compromise, The Kansas-Nebraska Act are all good to read about to get a better understanding of the sentiments of both northern and southern power brokers.

In the end, it had no where else to land but squarely on the issue of slavery. The southern states aristocracy held dearly to the idea of states sovereignty because it was their avenue to hold on to a favorable centralized power structure. The northern states elite class felt they were at a disadvantage economically as a result of slavery and needed the institution destroyed.

Yes, the main point of contention became slavery because it was central in the difference between 2 regional economies. However, the sparks that fueled the eventual inferno began far before the issue of slavery became the main point. It was the influx of large waves of wage demanding immigrants in the 30s, 40s, and 50s to the industrial north population centers that made the issue of slavery tantamount to its economy. Eventually resulting in slavery being the catalyst to conflict.