To begin, per usual, I'm mostly talking out of my ass here, so adjust your filters accordingly.
I don't think there has ever been a thriving civilization that didn't incorporate slavery. Even, here, in the U.S. (or maybe especially would be a more appropriate term) we have virtually countless cages stuffed full of people living a slave's life in all but name.
I'd like to propose a thought experiment that embraces slavery for the "people" who deserve, or need to be in chains, by subtracting the human element from the equation.
Ever since Citizens United gave corporate interests the same rights and privileges as people, I've hoped someone would be able to use it to criminally prosecute Big Interests who have a death toll associated with a negligence or malfeasance they've perpetrated, but thus far I don't know of anything, which I consider a problem.
Before going any farther, I'd like to momentarily divert attention to a concept 
I'd also like to point out that our forefathers greatly debated the limits of power corporations should have. I'm pretty sure TJeff wanted them dismantled after 20 years. Hell, that may have been policy somewhere, some time, but I digress. The point is, in crude terms, corporations are mammoths. If we're going to allow them in our society they shouldn't be allowed to run amuck and trample whatever is in their way. That's not to say we should hunt them to extinction, but I do think it's fair to consider them beasts of burden. After all, corporations are tools humanity created to serve us.
So with that in mind, I'd like to propose we consider giving corporations x years to operate, then periodically slice off a piece to give to the citizenry. Over time the slice gets bigger, up to a ceiling, or rather than a ceiling, it works for us full time with occasional furloughs. Either way, the balance of power is more distributed. I'd like thoughts and opinions. Later!