[rlmorel]

Slavery is incredibly inefficient component of an economic system it is factored into, and when placed alongside a capitalist system, it cannot complete. Back then, and with an agricultural based economy, that was probably the only thing keeping it going.

[DiogenesLamp]

I have little doubt that it would have eventually ceased to be profitable, and would have thereafter been eliminated mainly on that basis, but this process would have taken between 20 and 80 more years in my opinion.

But at the time, it was a big money maker.