I believe this is creeping bellflower, Campanula rapunculoides.
This is an aggressive self-seeder, and it creeps from rhizomes at the base of the plant. It is on some invasive species lists.
If you think this isn’t a match, please take photos of the inside of one flower, and the back of one flower, still attached to a stem, and I will take another look. Thank you for using our service.
I believe that is it. Makes me happy that the photo I took of it wasn’t my yard, LoL! Thanks for the kind assistance, Laura.
It is pretty though! You are welcome.