Within about five minutes I watched two yellowish, but very different, flying things.
Although first thought to be a Nashville Warbler, Carlo is correct (comments): This bird is a Common Yellowthroat.
The second is a Sulphur (butterfly), probably an Orange Sulphur. Sulphurs do not usually show the top of their wings, but this one had to as it lifted off from some aster.
How about a young Common Yellowthroat?
Nice flutterby!
Carlo, I have now spent some time exploring images. My sense is that the Common Yellowthroat has a beige belly, something my bird does not show. However, I am far from confident about this.
Good point about the belly colour. But the sharp demarcation between throat and dark head screams Yellowthroat at me. Also plain uppers. Can’t think what else it might be.