I was returning home when I spotted a bunch of these flowers in one small area along a country road. I first thought they were phlox, but phlox has 5 petals. This plant has deeply serrated leaves.
@redrucksack - Thank you Eva!! I looked in a wildflower book I have and the closest one I could find is called Dame's Rocket. This plant has serrated leaves where phlox and Sweet William's don't plus these only have four petals.