A couple of folks have mentioned Norton in this thread, but Norton (and Cynthiana) are pure vitis aestivalis. No cross, no hybrid, just an American grape variety of its own.

We drink a decent amount of Missouri stuff - white and red. The value is not great, but I'm willing to pay a couple of extra $$ to support local folks trying to make good wine. The biggest problem here is finding people who keep the residual sugar remotely in check.