But I keep under my body, and bring it into subjection: lest that by any means, when I have preached to others, I myself should be a castaway.
1 Corinthians 9:27
It was ended by Christians Elon: first in by monks towards the 8-10th centuries, and again in the 18-19 centuries in the Transatlantic slave trade. You had both white and black abolitionist; what glued them was the Christian theology. And it was precisely jewish theology that infected Christendom after it had almost effectively eradicated slavery on the European continent, that reintroduce the ancient slave practice and provided the moral/theological justification for it.
Trivia: some of the most important slave-ship and plantations owners of the New World were jewish. Hear professor Tony Martin, who lays it out.