It apparently seems to be foreign to you, so no doubt you can’t understand, but feeling that slavery trumps the constitution does not give you the moral high ground. You’re in the same boat as the Confederacy, like it or not.
That war was never about slavery anyways. If it was, the slaves that the north ‘freed’ wouldn’t of been pressed into service.
There are some horror stories to be sure, but there was also a lot of ‘slaves’ being treated decently and lots didn’t want to leave.