"1. In every political movement there is a leader or leaders with a motive."
I would make this observation that the secession movement in South Carolina, which eventually snowballed to include the whole South, started well before 1860 and even before the 1832 South Carolina Nullification Crisis. That this Nullification Crisis had nothing to do with the abolishion of slavery, or at least very little if any. But did seem to have it foundation it trade disputes. This is the same reason behind the Hartford convention in the New England States a few years before that. The reasoning behind that feeling that South Carolina needed to seceed at that time, in 1832, and President Jackson responce by use of intimidation, seems to have planted the seeds for the possibility of the need of secession throughtout the south.
It is my opinion that as with most everything else, if you follow the Money you will find the motive. Therefore to find the reason, and the leaders, of the political movement, you must look at the enocomic leaders for their influence on those political leaders. Which is a harder thing to do since they (the economic leaders) operate mostly behind the scenes.