There are several natives. It may be Heliopsis helianthoides, Smooth Oxeye Daisy. It grows well in my yard too, from seeds from NC Bot Garden. It bloomed first year, and spreads by seed and underground runners.

Thanks, that could be it, but I'm not sure. It looks like there are about 26 species in NC, according to usda.gov!

I was hoping to collect a sample, but D.O.T. mowed them all down a couple of weeks ago.

Turns out it wasn't helianthus at all.

It was Bidens aristosa, "tickseed sunflower".