Here I agree with you. I think the economics of it would have failed too, but it might have taken between 20 and 80 years for that to happen. Social pressure would have never abated, and state by state, the South too would have succumbed to the influence that had earlier purged the institution in the Northern states.
But to the bondsman, a generation or two is his entire life.
In the calculus of the lesser of two evils, I lean toward believing it would have been better to not have killed 750,000 people in war directly, along with the claimed 2 million who died as a result of starvation, disease and exposure, as well as setting up the Omni-powerful Federal Leviathan we have now and eroding our original rights as independent states.
What we have now is more lingering and more extensive than what would have resulted from slavery declining naturally.
It’s the “peculiar institution”.