I posted this to Facebook to get an identification since I had never seen one of these before.  It is larger than most bees, about 1.5 inches long, and never stops moving.  It took me a long time to get a shot, it kept moving counterclockwise around a butterfly bush and after observing this for a while, I just waited for it to come around and finally got lucky.  I am told that this is a European Hornet and it is apparently the only true hornet found in the U.S.