The Left acts like the US Government invented the concept of slavery in 1620 and persisted in the slave trade until 1865 at which point slavery on Earth ended and was replaced, by the US government, by Jim Crow.
Slavery is old.
The US government consistently tried to reduce slavery in our territory.
Jim Crow is strictly a Democrat thing.
Slavery persists today, but it does so outside the US, with slave owners being almost exclusively dark skinned.
If anything, we are the Good Guys in this story.
And if you consider that Massachusetts abolished slavery in the 1780's, parts of this country were among the first on the planet to do so.