Jimmy Akin has a lot to say about the “dark passages” in the Bible.
Here is his opinion on Jesus v Slavery, not sure if it is what you were looking for:
Her is another article on wh God allows suffering:
Here is an article by Akin in the NCR on why God allows sin and suffering:
Also the Church always condemned so-called “chattel slavery” where human beings were treated as property, and Pope St Pius V forbade slvaery in the new world (whch the Spanish and Portuguese authorities sadly ignored). The type of slavery practiced by the Israelites was more a form of indentured labour in which the servant had some kinds of rights against his owner (not saying that’s a good thing, but labour relations were not in their infancy) and religious festivities often required the freeing of slaves.
I will post new articles as soon as I find them.
Also clerics like St Peter Claver and Charles Martial Lavigerie (founder of the White Fathers missionary Priest order) were strong campaigners for the abolition of slavery.
During the US civil war, the senior Catholic Bishop, John Hughes, supported the union and Lincoln even sent him as an envoy to Italy and France to counter pro-southern sentiment there.