We had those in the field behind the house where I grew up in Springfield, Mass. IIRC, they're also called blue racers because sometimes the light hits their black skin and looks blue. Fast SOB's, and quick to bite a nosy 8 year old kid...
but, they're one of the truly beneficial snakes, and we never killed them. We also had copperheads...those we killed when we found them. (stupid 8 year old kids...copperheads can be aggressive when threatened.)