Looks like Virginia Bluebells (Mertensia virginica)to me. It is a native woodland plant that is ephemeral. Mine is dropping some seed now and then will die back down to ground until next spring.

The leaves don't look like campanula.

Hi I agree that they are virginia bluebells They go dormant in the summer after the blooming is finished so mark the site so you won't disturb them and next year you should have an even better display . enjoy Lois

Yes, I agree too - virgina bluebells!

Dee