I agree that slavery would have ended at some point. Slavery was an expensive proposition in that those enslaved really weren't interested in working and the cost of their care, e.g., clothing, food, et al expenses. Couple that with the fact that we were on the cusp of the industrial revolution and one could easily predict slavery's end. The cotton picking machine, for example, requires only fuel, oil and occasional maintenance. And, it doesn't create any social problems.
As for the remainder of your missive, all I can say is that everyone is entitled to their own opinion however erroneous it might be.
The first commercially successful mechanical cotton harvester was also not introduced until the late 1930's. Kind of long for the slaves to wait, don't you think?
I don’t see how those who believed in slavery would have offered freedom to others...also I am from the South essentially-military brat-lived all over including the South. Mom is a Virginian...old family. There was really a caste system in the South even after the end of slavery...best families...Byrd etc.