Kind of like the US constitution prior to the civil war. On the other hand there are no statements that slavery is good. It's routinely considered a bad thing throughout the Bible.
If you're looking for statements of modern sensibilities in the Bible you're not going to find them. It's a 2000 year old book written in a very different time.
The books of Galatians and Philemon contain pleas to free slaves but you'd have to do a lot of research into the early Christian writers to see what they really thought about where slavery was going. The real crime is that slavery still exists today. However, it's rare in the Christian parts of the world.
LeviticusSeems rather straightforward.
25:44 Both thy bondmen, and thy bondmaids, which thou shalt have, shall be of the heathen that are round about you; of them shall ye buy bondmen and bondmaids.25:45 Moreover of the children of the strangers that do sojourn among you, of them shall ye buy, and of their families that are with you, which they begat in your land: and they shall be your possession.
25:46 And ye shall take them as an inheritance for your children after you, to inherit them for a possession; they shall be your bondmen for ever: but over your brethren the children of Israel, ye shall not rule one over another with rigour.