We were at a nice camping resort. It's possible the owner introduced a 'wildflower mix' at some point for the Verbena and Vernonia. I don't know if those are common additions to planting mixes or if they are truly common there. There were meadow areas around the site.
The rest were in wild locations near Saxton PA (tiny town) and Raystown Lake, except the Verbesina (wingstem) was along the C and O Canal in Hancock MD