text: was it democrats or republicans that was anti-slavery? please explain. i would prefer 3rd party people answer. just wondering how this worked back then. i must have been sleeping during that part of history.  please, no getting angry or any name calling. slavery was abolished because it was plain out evil. that much is the truth and anybody with any brains at all knows that. the parties were different back in that day they have sense switched platforms pretty much with each other.  lincoln was then a rebublican but would be a modern day democrat....  the rebublican party was the more progressive/innovating party the democratic party was set in the ways things were done