The Southern leadership was the agrarian leadership after the Northern landholders (such as the Knickerbocker patroons) were overreached and surpassed in the early 19th century by the Millocracy, and the northern version of the deferential society was replaced by the commercial model.
I've said it before and I'll say it again -- all those Western farm States that sent big brigades to fight for Grant and Sherman just never got it. They never understood the issues -- because smart guys like Cameron, Stanton, Chase, Seward, and Lincoln kept their eyes on the slavery issue.
Some people still don't get it, and still don't realize that all the Western States and Territories fought on the wrong side in the Civil War, except for the mining-centered ones like California, Colorado, and Nevada.