Most folks probably don't consider the famous Café du Monde in New Orleans to be a diner, but I contend that it really it is.
Located in the French Market District (
not the French Quarter), on the Mississippi riverside, Café du Monde is open 24 hours a day, except for Christmas Day and hurricane days. (Katrina shut it down for weeks.) It is busiest at breakfast time, and serves breakfast all day long. It is famous for its coffee. Sounds like a diner to me!
Their signature coffee is cafe au lait: "The Café Du Monde Coffee and Chicory is traditionally served Au Lait, mixed half and half with hot milk." (New Orleans in the the only place I drink coffee with chickory; heck, when in Rome . . .).
The original French Market stand was opened for business in 1862 -- when Lincoln lived in the White House. Now, that is history and tradition! Over the past 35 years, they opened 7 other locations, and two gift shops, all in the greater New Orleans area. Along with cafe au lait, they specialize in Beignets. "Beignets were also brought to Louisiana by the Acadians. These were fried fritters, sometimes filled with fruit. Today, the beignet is a square piece of dough, fried and covered with powdered sugar. They are served in orders of three."
"Coffee is strong at the Cafe du Monde
Donuts are too hot to touch
Just like a fool, when those sweet goodies cool
I eat til I eat way too much"
Jimmy Buffett, "The Wino and I Know"