Campanula ranunculoides. Not native. There is a name that plant forum which is where most people go for identifications but we get many of the same people visiting this forum so it all usually works out in the end.

Thank you. I'll be sure to use that forum when I need ID assistance again.

The area where this flower is will eventually be cleared out, and I'll be putting gravel there. I've decided to try to salvage the random nice flowers that pop up there from time to time-particularly hummingbird friendly plants. A couple months ago I found some nice garden phlox and put it in a flowerbed in our yard.