Quick comment on the whole "% of slaveowners in South" debate:
Looking at my Lincoln Museum guide there is a very pro-Union graph that displays certain percentages of things in Northern and Southern states. There is a graph that is "Whites in the Slave States" vs "Slave Owners in the Slave States". Owners make up about 8% of the white population.
Sure, it's an old graph and it's biased. . . . .towards the Union.
It is not that relevant that only a small percentage of whites in the South owned slaves. Slaveowners controlled the politics and called the shots, and most (though not all) Southern whites respected them. Actually, it would be quite accurate indeed to claim that slaveowners formed an even smaller percentage of the region's population, since many people in the region were SLAVES. Majorities of people in South Carolina and Mississippi were enslaved, and it was over 40% in Louisiana, Alabama, Georgia, and Florida. So yeah, obviously slavery could not have been the main reason for secession since only a few bad slaveowners benefited from the institution anyway. At least that's the logic that some people have.