CHAMBERSBURG, Pennsylvania — It is early Sunday morning along one of the few congested stretches of the Lincoln Highway when an empty parking lot below the familiar cheery yellow sign for the local Waffle House catches the eye.

The 24-hour diner chain, born in Atlanta 65 years ago and now spread across 25 states in nearly 2,000 locations, is primarily known for its ability to serve as a touchstone in every community it serves. It feeds a cult-like following among foodies and road warriors.