I didn't respond because it is foolish to do so. But, because you seem to want to force the issue, here it is.
The issue is a moot point. OBVIOUSLY, the owners found they COULD work the mines, fields, factories, etc., without slaves, because they did.
If you want to make the comparison to the continuing work, without slaves, to today's industries that use Mexican labor, go ahead. To conservatives, the market bears what it can. To all liberals, the market can bear what they FORCE upon it.
And force would be a disregard for this country's laws and the will of the people?
Free society cannot bear just whatever the market can bear. We cant have slavery, abusive child labor or the murder of individuals for the purpose of selling their organs regardless of whether there is a market for it or not. We live in a society of laws, a country with borders.