Slavery actually flies in the face of our foundational documents unless you dehumanize a certain class of people which is ironically exactly what abortion does.

What allowed slavery at a federal level was the dred Scott decision by the supreme Court in 1857. This ruled that African Americans weather enslaved or free were not citizens and The Constitution in the Bill of Rights didn't apply to them.

The same supreme Court that made a similar mistake with Roe v Wade. The same supreme Court that recognized gay marriage.

If we simply accepted the fact that African Americans were made in the image of God with all the inalienable rights of everyone else than we wouldn't have even needed the 13th amendment.

The federal government didn't free the slaves. They recognized they were people finally.