The Charcoal Pit has been serving burgers on Concord Pike in Wilmington since the Happy Days of the Eisenhower administration, when a 4-ounce hamburger was considered a meal rather than an appetizer. (Funny how, in the GLP-1 era, that portion suddenly seems just about perfect.)

This is honest food. The signature flame-broiled burger, ordered medium at my recent stop, arrived precisely that way — juicy and properly pink inside, speared by a charming retro toothpick helpfully confirming “medium.” The fries were similarly old-school: unevenly golden, crisp at the edges but softer through the middle.

Everybody heads to the Pit’s soda fountain, where we all skipped the idea of the 20-scoop “kitchen sink” sundae in favor of a more manageable three dips: Pistachio and peanut butter swirl are two winners.

Burgers, shakes, and sundaes never go out of style, and neither does this dining room. The Charcoal Pit looks less like a recreation of a 1956 diner than one that never got the memo the 1950s ended.

Despite renovations, enough survives that the nostalgia feels accumulated rather than contrived: red vinyl booths, a black-and-white checkerboard floor, saucer-shaped pendant lights, and mirrors multiplying the chrome stools and booths.

One bit of history is more consequential. An oft-retold story holds that around 1960 or 1961, Joe Biden and several Archmere Academy football teammates walked out after the restaurant refused indoor service to their Black teammate, Frank Hutchins. Teammate Michael Fay later recalled Biden leading the walkout. As an adult, Biden frequented the Pit, stopping particularly for its butter pecan ice cream.

And one practical tip survives from a more innocent part of the past: Always put the kids on the inside of the booth, so they can reach the free-play jukebox and flip through the 1950s hits.

Charcoal Pit, 2600 Concord Pike, Wilmington, 302-478-2165, charcoalpit.net