Slavery is a monstrous injustice that deprives our republican example of its just influence in the world and enables the enemies of free institutions, with plausibility, to taunt us as hypocrites.
Slavery is a paradoxically self-destructive logic whereby masters try to justify their privilege as top-humans by dehumanizing their slaves (via rape, beatings, and other brutalities) which only results in them dehumanizing themselves.
Slavery is also a mental state, such that as long as one is scared, one is, so to speak, on the plantation.
Slavery almost ended in 1784 when Thomas Jefferson proposed ending it. His bill lost in Congress by a single vote.

Slavery is still one of the biggest profiting trades in the world; there are an estimated 40.3 million slaves worldwide.
Slavery was a huge industry in the US --- There were an estimated four million people living in slavery in the United States in 1860.
Slavery is abhorrent and grossly inconsistent with the principles of the declaration of independence (but not worth a flaming denunciation).
Slavery was no small business --- In 1860, there were an estimated four million people living in slavery in the United States.

