MECHANICSBURG, Pennsylvania — When you pull into Legacy Park, you can tell it was a farm just a few years ago. Today, the development is home to a yuppie brew pub, a soap boutique, and an environmentalist-themed coffee shop called Down to Earth Café, whose motto is “coffee with an impact.”

The clientele is upper-middle-class young families or retirees who arrive in Japanese cars and puffer coats. The staff have dyed hair and all sorts of piercings. Cumberland County is changing.