@Sanguine @Smokin Joe
Here's a little Marx for you!
Karl Marx, 1861
Karl Marx
I have long maintained that the threat of Abolition wielded by the North was an Economic threat, first and foremost.
Not only would the wealthiest (as well as the small slave owner) be divested of major assets (slaves did have considerable value), but would be deprived of the necessary labor to raise and harvest the crops which were the backbone of the Southern economy.
That the South sought to secure that vital part of the economy would be no surprise, but that was only one facet of the economic fight, and the last straw as far as many were concerned.
Slavery, with the influx and migration of large numbers of European immigrants would have died on its own accord. The supply was so massive, that not only could Northerners be selective in who they hired ("The Irish need not apply"), but they used them mercilessly as cannon fodder, even paying immigrants to go to war to escape conscription. The economics of paying someone a wage and letting them fend for themselves for housing, food, medicine, and not having money invested in their existence would have lured the vast majority of slave owners to manumit. Slaves in much of Maryland were increasingly being freed before the war, because the nature of the agriculture practiced there no longer required as many to grow and harvest the produce demanded by the expanding populations of the Federal District and Baltimore.
When the economics of long term costs versus revenue are weighed against purchase price, the equation works out that it is cheaper to free slaves and hire them back or hire immigrants who have no up front investment burden, and can be fired at a whim. When there is no longer any necessity to pay for housing food clothing etc. (to maintain that initial investment) company store arrangements can be used to recoup part of the wages (or all of them) and debtor laws leave those who are profligate in their spending in thrall as serious as slavery.