There were as many who did so as there are water molecules lacking any hydrogen or oxygen.

Slavery is about the maximum in treating someone badly, so basically by definition you can't treat someone well and also enslave them. We can make distinctions within that framework and individuals do vary, but it's absolutely vital to keep in mind that we are still speaking of slavery and slavery is always about maximally awful. But as I've written on this beofre I'm going to shamelessly rerun that. Further questions and follow-up are absolutely welcome.

Thousands of people who own millions of other people over two and a half centuries are going to have some differences between them and those millions of enslaved people will not all have the same experience of slavery. Among themselves, the enslaved would sometimes argue over who had a better or worse enslaver. Likewise some enslavers considered themselves humanitarians, at least sometimes, or otherwise tried to be "one of the good ones". (Many of these seemed to think they were owed more dutiful, harder work as payment for a few slivers of patronizing human decency, of course.) They also commented on their peers' enslaving practices, consumed pamphlets and editorials on how to best enslave, and so forth. A range of behavior existed, with some people more violent, exploitative, cruel, rapacious, and all the rest than others.

But slavery is an inherently cruel, violent practice. There's no way to do it without all that, because once one starts consistently treating the people one enslaves as human beings worthy of equal treatment, one has ceased enslaving them. The enslaver with the lightest touch is still an enslaver and extracts obedience through the threat of tortures not yet given. Some of them, sometimes, make an argument that it's better for them to keep enslaving people than to sell them or allow them to be sold to someone who will enslave them in a worse way still.

Say all of that's true. We have an enslaver who treats the people he enslaves relatively well, aside from the fact that enslaving in the first place that wipes out any possibility of such a thing. By holding people as property, our enslaver still hasn't freed them. He can change over time and become cruel. He will eventually die and his heirs might be cruel. He can get in financial hot water and have the people he's enslaved seized for his debts and then sold at auction or taken as in-kind repayment by others who will be worse. The life of every enslaved person is fundamentally insecure. Whatever happiness and stability they enjoy depends utterly on the fortunes and whims of another not of their choosing, who can destroy their families, their bodies, and their very lives.

The very best an enslaver could do is free those he enslaved and pay them considerable reparations so that they could establish independent, secure lives of their own choosing. Very few enslavers could ever be asked to do that, and fewer still were the kind of zealous white advocates that free blacks would need to preserve what they have and improve their lot in a civilization bent on reducing them back to slavery or expelling them from itself. Of those few who even bother, the rarity among the rarities would be an enslaver who frees and provides for all the lives they have stolen.

A case in point here is Edmund Coles, a relation of Thomas Jefferson's. Coles never, to my knowledge, bought a person. He grew up in an enslaving family and inherited about fifteen people. He wanted nothing to do with slavery and decided to be quit of it as soon as he could. For Coles, that meant taking the people he now enslaved out to Illinois. There he bought them all plots of land and freed them. Then he stuck around in Illinois and fought the move to legalize slavery there. But he never asked them if they wanted to go to Illinois, at least so far as I've learned. Maybe that was a better deal for them than Virginia, but they were still property so they had no say in where their home would be. Even in the very best case scenario, it ends with an enslaver ceasing to enslave and we still have fundamental issues about respecting individual freedom.

From what I know of Coles' situation, he worked to minimize the harm he was doing, but he was still a party to an egregiously violent system built upon human degradation to the maximum possible degree short of death itself. It's not his fault that he inherited someone else's human property, but he did exercise his prerogatives as an enslaver in setting the course of those lives. By removing the people he enslaved from Virginia, he cut them off from friends and family left behind. Imagine losing everyone you knew and loved. The enslaved tell us time and time again that that loss was their greatest fear, more serious than death itself. In doing the best he could, Coles still took away the people they loved, never to see them again. This is a loss just the same as if Coles had murdered all those people. The details of the act matter, but the pain comes from the loss. Coles bereaved fifteen people in order to free them and do right by them. He did what most of us probably consider a good thing and what might well be the least worst thing he could possibly do given his resources and abilities, but it's still a hard, bitter, agonizing thing to be taken from everyone you love and have everyone you love taken from you.

Whether that makes Coles good, a lesser evil, or pure evil still isn't really a question I can answer from a historical perspective. They aren't terms we regularly use in analysis, even though almost every historian working in the field today believes slavery either the absolute maximum in immorality or close to it. Coles thought he did good. Jefferson, who he asked for advice on the plan, though he did bad. To the best of my knowledge, we have no surviving evidence of what the people actually involved thought. By the time they found out, it was a fait accompli so they lacked even the opportunity to leave evidence of their reaction by choosing to steal themselves or cooperate. The best we can do as historians is try to understand the complexities they faced and never lose sight of the horrors inherent in the system.