> Black American slaves did not earn wages.
Not usually, no.
>Their sentence was indefinite.
Or even infinite, as far as they were concerned.
>As soon as they stopped working, they were executed.
Whoa, hang on. I'm not a slavery apologist, but... are you sure? As in, routinely, not as a bizarre, rare event? Not events like lynchings, but just "well Old Tom here ain't producing anymore, time to string him up"?
I have read some of the work of actual slavery apologists, and one of the points often made is that laws prohibiting manumission of slaves were originally written in response to owners who would free their slaves when they were too old to do the work - and promptly dump them out with no money, no education, no place to live, and no skills beyond basic agricultural labor, to die. I could imagine that was an issue.
The wrongness of slavery is often talked about strictly in terms out of Uncle Tom's Cabin, though a point often made in early abolitionism was that the creation of an entire inheritable status of sub-citizens was evil in itself, regardless of how well or poorly the sub-citizens were treated. Also treated interestingly in Orson Scott Card's Tales of Alvin Maker (which are not great books, but sure do give you some insight into Card's Mormonism), where the South remained royalist in the American Revolution. It certainly could have, if George III had better positioned his treatment of the colonies. The basic organization of the early South as an agricultural region centered on individual properties owned by some noble (who might or might not live there) and organized like medieval village life. Roads to get to neighbors were relatively unimportant, as water transport was the norm for both people and cargo. The entire coastal and tidewater area from the Sea Islands of Georgia to the Chesapeake worked like that, at least until colonists started trying to push past the limit of navigation (which made large plantations more difficult until you got south of the foothills of the Appalachians).