150 years ago, if you worked an Irish or Polish or Chinese or Italian laborer to the point they could no longer work, no big deal; there’d be plenty more fresh off the boat tomorrow, eager to take their place.
If you worked a slave to the point they could no longer work, you were out a considerable capital investment.
My son, back in junior high had to write an “argumentative” paper. He figured the hardest one to write would be to show that slavery in America was good.
That was one of his points. The importation of slaves was outlawed at some point, so it was in the slave-owner’s best interests to keep the slaves alive, let them have their own social networks and churches, and to let them have families.
He got an “A+” on the paper. (in a VERY liberal part of the country!)
It was tragic how many slaves died in the Caribbean and S. America during the same time period.