There’s a pretty famous book and then film about what you are talking about so not sure why I wouldn’t at least be aware of it. Feudal society had slaves and serfs, who also had to sometimes flee to other countries as they where not allowed to leave the land/lord they were bonded too.

The “Northern States” also mostly had slaves until just before the civil war, if less prevalent than the “South”. It wasn’t fully the same economy at the end of the day.

I just don’t understand what you are arguing ? Do you take offense from the previous commenter using the word slavery is that it?