I still think you are responding to a comment two levels up from mine. I entered the thread saying that as a "moral leader" owning slaves reflected badly on Jefferson[1] - Certainly, the fact that slavery was allowed by the constitution made it less of a good document, but if you note, I didn't say that owning slaves diminished his role as an author of the constitution; I only said that owning slaves diminished his standing as a moral leader. Of course, writing a constitution that accepted and protected slavery diminishes his standing as someone who wrote an important document on the road towards progress, because even by the standards of the time, that was not particularly progressive.
I personally wonder how necessary a constitution is for a functional republic; it is supposed to protect the rights of the minority, but I'm not sure the historical evidence comes out in that direction.
To more directly address the question, I honestly don't know. My first instinct is to exclude the south. Of course, that excludes most of the founders. But think of what an industrial powerhouse we would have had to become to survive, without the agricultural money. Would we have made it without them and the agricultural money, which mattered a lot more back then? would they have joined us in a more peaceful sort of way? Would we have ended up conquering them anyhow, and perhaps subjugating them in a way that ended up being better than what happened during our timeline, the appeasement in the name of unification? I don't know.
[1]https://news.ycombinator.com/item?id=14698270