Clams Casino

John Mariani's Encyclopedia of American Food and Drink (1999) states:

"A dish of clams mixed with butter, paprika, and shallots, then baked with small strips of bacon on top. The recipe originated at the Casino at Narragansett Pier in New York City [sic] around 1917. In his autobiography, Inns and Outs (1939), restaurateur Julius Keller described how society woman Mrs. Paran Stevens asked Keller, then maitre d' at the Casino, to create a new dish for a luncheon she was holding for friends."

The dish might have been first created at Rhode Island's Narragansett Pier Casino or at New York City's Central Park Casino."Soft clams a la Casino" is on a menu from the Central Park Casino that the New York Public Library's menu collection dates to January 17, 1900. "Soft clams, Casino" was on a 1903 menu at New York City's Hoffman House.


Wikipedia: Clams casino
Clams casino is a clam "on the halfshell" dish with breadcrumbs and bacon. It originated in Rhode Island in the United States. It is often served as an appetizer in New England and is served in variations nationally.

Ingredients
The dish uses littlenecks or cherrystone clams. Other basic ingredients include butter, peppers, bacon and garlic. Worcestershire sauce, salt and pepper, white wine, lemon juice, and shallots or onion are also used. Tabasco sauce is sometimes added, and parsley is sometimes used as a garnish.

Google Books
The Financial Side of Hotel Keeping
By J. Elliott Lane (Charles Martyn)
New York, NY: The Caterer Publishing Company
1903
Pg. 269:
The Hoffman House
Supper

(...)
Soft clams, Casino 60

Google Books
Explanations of All Terms Used in Coockery [sic] - cellaring and the preparation of drinks:
Pocket dictionary

By Kurt Heppe
New York, NY: K. Heppe
1908
Pg. 50:
Clams, Casino -- baked in shell, bacon and peppers.

18 September 1916, Washington Post, pg. 10:
Harvey's Seafood Platter Today, 12 to 3, 6 to 8:30, 50c

Clams Casino, Crab Flakes Newburgh, Fried Oysters, Potato Salad and Slaw. Other seasonable delicacies.11th and Pa. ave.

4 March 1943, New York Times, pg. 14:
"Clams Casino" Easy to Bake"
Speaking of fish, a market on upper Lexington Avenue sells something called "clams casino" that are worthy of investigation. These come ready to pop in the oven and cost 85 cents a dozen.

In describing their preparation, the proprietor explains that the fat centers of two soft-shelled clams are arranged in a clam shell and garnished with chopped chives and strips of bacon. The shells then are packed on ice in sturdy cardboard boats. Upon delivery, they need only be removed from their container and baked for some ten minutes, or until the topping turns a delicate shade of brown. Though the clams are used primarily as an overture to dinner, they may pinch hit for a main course if accompanied by vegetables and a salad. Oysters casino are also available in this shop for the same price.

9 July 1950, New York Times<.i>, pg. SM15:
IN contrast to the elaborate richness of the above, this bit of simplicity from Billy the Oysterman, 7 East Twentieth Street:

SOFT-SHELL CLAMS CASINO
Remove the necks of soft-shell clams and stringy portions around sides of shells. Chop very fine. Put soft center of each clam in a shell. Add enough minced celery, minced green pepper and chopped clams to fill shells. Cover each with a short piece of bacon. Broil under a moderate flame or bake in a moderate oven (375 degrees F.) till bacon is crisp.

Eater
Digging Up the History of Clams Casino, a New England Classic
by Erin DeJesus , photos by Chris Almeida Jan 29 2015, 12:03p
(...)
The dish is most often credited to Julius Keller, who claimed to have invented the dish when he was an employee at Rhode Island's Narragansett Pier Casino. Contrary to its name, the Narragansett Pier Casino was not a gambling hall, but instead an upscale resort property built in the mid-1880s.
(...)
Julius Keller was a Sherry employee, and in his 1939 memoir Inns and Outs, he lays claim to the dish: In Keller's account, one of the resort's guests, Mrs. Paran Stevens, requested a "special" clam dish for an eight-person luncheon she was hosting. Those eight guests were the first to taste what Keller called "clams casino," and according to Keller's memoir, his diner was rather pleased. "My introduction of them to the socially ultra Mrs. Stevens put me in her good graces for the remainder of the time I spent at Narragansett," Keller wrote. (A historian at Johnson & Wales University found a rare surviving copy of Keller's book in 2005, bringing the origin story to light.)