A “hot dog” is often called a “Coney Island,” or “Coney” (“coney”) for short. Sometimes, it’s “coney dog.” “Coney Island (sandwich)” has been cited since at least 1882, but “coney dog” is a term that was popular with 1950s drive-ins.
     
See also “frankfurter,” “hot dog” and “red hots.”  A coney with “coney sauce” is a popular dish in the Midwest (especially Michigan), but this is not the Nathan’s-type hot dog that is served on Coney Island itself.
 
 
Wikipedia: Coney Island hot dog
A Coney Island hot dog (also Coney dog) is a hot dog made from beef with casing, topped with an all meat chili, diced yellow onion and yellow mustard. The product described in this article was primarily developed in Michigan, and served there and in the “heartland” states; that is, the non-coastal states of the U.S.. In parts of Southern California the meal is called “Beecher’s Revenge,” or, “the Shapely-Brow Special” in reference to the famous Malibu eatery.
(...)
Description
In many locations, a “Coney Island hot dog” includes “coney sauce,” which is generally a beanless chili. This variation of the “Coney Island hot dog” is thought to have been invented in the state of Michigan by various claimants (such as Todoroff’s in Jackson, Michigan or American Coney Island in Detroit). As a result, Coney Island hot dogs featuring “coney sauce” are prevalent around the Midwest United States, particularly in Detroit, Michigan. In general, the phrase “Coney Island hot dog” is now used primarily to refer to the version with chili sauce. In southeast Michigan, a number of casual dining establishments are called “Coney Island restaurants” indicating the popularity of the chili dog. 
 
Wikipedia; Jackson, Michigan
Jackson is a city located in the south central area of the U.S. state of Michigan. It is the county seat of Jackson County, Michigan6. As of the 2000 census, the city population was 36,316. It is the principal city of and is included in the Jackson Metropolitan Statistical Area.
(...)
Coney Island heritage
Jackson is known around Michigan for its famous Coney Island-style hot dogs. The Coney dog has been a Jackson mainstay since the early part of the 20th-century. Coney Island hot dogs typically contain “everything”, or meat sauce, mustard, and chopped onions. Unlike neighboring Detroit style Coney dogs, the sauce at most Jackson establishments more closely resembles crumbled ground beef than the more traditional chili con carne, runnier sauces found in Detroit. Many area residents have fond memories of eating Jackson’s Coney Island hot dogs.
   
Many Coney Island restaurants are still active today, including:
Jackson Coney Island
Virginia Lunch
Alpha Coney Island (Detroit style)
Christoff’s Corner Coney Island
Todoroff’s Coney Island
The Roxy Café
Andy’s Pizza & Coney
Tommy’s Coney Stand
Omega Koney Island (Detroit style)
The Dog House
 
Wikipedia: Michigan hot dog
A Michigan hot dog or, “Michigan”, is a steamed hot dog on a steamed bun topped with a meaty sauce, generally referred to as “Michigan Sauce”. The sauce may or may not be tomato-based, depending on where the Michigan is purchased. Michigans can be served with or without chopped onions. If served with onions, the onions can either be buried under the sauce or sprinkled on top of the sauce.
 
Michigans are a particular favorite in the North Country of New York State, and have been so for many decades. In fact, one of the earliest known advertisements for Michigans appeared in the Friday, May 27, 1927, Plattsburgh Republican.
 
Michigans are also very popular in Montréal and other parts of Québec, where the sauce that is put on them is invariably tomato-based and is often simply referred to as “spaghetti sauce”. Lafleur Restaurants, a Québec fast food chain, is known for its Michigans and poutine.
 
Oddly enough, “Michigan hot dogs” are never referred to by that name in Michigan itself, nor anywhere else in the Midwest. A similar food item, the “Coney Dog” or “Coney Island dog”, is a hot dog topped with onions and either chili or a meatless chili called coney sauce. Conversely, the “Coney Island” is not called as such on Coney Island, or anywhere else in New York State; it’s called either a “Michigan” or a “Red Hot.” Finally, in southeast Michigan, a “Coney Island” is also the local slang term for a greasy spoon.
 
The Origin of the Michigan Hot Dog
Although there are many different varieties of Michigan sauce available today, the original Michigan sauce was created by Mr. George Todoroff in Jackson, Michigan. The sauce was originally created to be used as chile sauce. In 1914, Mr. Todoroff took his recipe to Coney Island in Brooklyn New York and opened his first restaurant. However, the hot dog hadn’t arrived on the scene when he first opened his restaurant, so he had to wait until 1916 to make his first famous “Jackson Coney Island” hot dog. Todoroff’s restaurant in Jackson remains in business to this day.
   
Todoroff’s Original Coney Island (Jackson, MI)
George Todoroff
George founded the Jackson Coney Island restaurant in 1914. He created his famous recipe for Coney Island Chili Sauce, and the Coney Island hot dog was born. He also created his recipe for Chili Con Carne. George’s Jackson Coney Island offered a menu of Coney Island hot dogs, Chili Con Carne, baked beans, pies, soft drinks, beer, and wine.
 
His Jackson Coney Island restaurant was located in front of the Jackson Train Station on East Michigan Avenue and was open 24 hours everyday. Many of the train engineers and conductors, and passengers, would walk into the restaurant through the back door for a lunch of Coneys, a plate of baked beans or a bowl of Chili Con Carne, and a beer. During the next 31 years, he sold 17,000,000 Coney Islands. George retired in 1945.
(...)
THE CONEY ISLAND HOT DOG
The All-American hot dog has been around for a long time. George Todoroff improved this American favorite when he created his famous recipe for Coney Island Chili Sauce in 1914. He added this one-of-a-kind jewel to the hot dog, along with mustard and onions, and the Coney Island hot dog as we know it, was born.
 
Old Fulton NY Post Cards
22 June 1882, Newtown (NY) Register, “Newtown Official Muffers,” pg. 5, col. 3:
The refreshments on the occasion will be provided by Monteverde, and any guests with two nickels in his pockets can indulge in a glass of lager and a Coney Island sandwich.
     
Old Fulton NY Post Cards
16 September 1887, Philadelphia (PA) Inquirer, “Chips From the Great Pageant,” pg. 3, col. 5:
The fakirs reaped a rich harvest with “peanuts, hot sausages, Coney Island sandwiches,” and many other delicacies too numerous to mention.
 
Chronicling America
26 November 1888, The Evening World (New York, NY), “The Tramps,” pg. 1, col. 3:
In a space where the circus arena is laid, fifty fakirs made a deafening din in their efforts to lure the cash from the pockets of a gullible public in exchange for Coney Island sandwiches, muddy coffee, two-for cigars and other undesirable commodities.
 
5 March 1889, Atlanta (GA) Constitution, “President Harrison; Inauguration Ceremonies,” pg. 1, col. 6:
Indeed, the visitors were not likely to go hungry, for under many of the grand stands, booths had been set up where abundance of sandwiches and fruits could be had, and “no extra prices” as the placards declared. A legend familiar to New Yorkers on some of these stands read “Coney Island sausage sandwiches.”
       
5 July 1889, Boston (MA) Herald, “Scenes on the Common,” pg. 3, col. 2:
Mountains of glucose, cakes, prize packages, hokey-pokey, hot Coney Island sandwiches only 5 cents each, ...
 
6 September 1895, Syracuse (NY) Daily Standard, pg. 6, col. 7:
This meat has been sold to a sausage maker and would have been all bound (? illegible—ed.) up into red hot Coney Islands had it not been for the city’s officer.
 
1 August 1897, Syracuse (NY) Herald, pg. 13, col. 1:
There were peanuts and pop corn, hot Coney Islands, fruit and candies sold as well as large quantities of intoxicants and soft drinks.
 
14 August 1898, Syracuse (NY) Herald, pg. 21, col. 4:
Purveyors of red lemonade, “California” peanuts, watermelon and “Coney Islands” are tenderly greeted and well patronized by the people who hie themselves away for a day’s outing at Howlands Island.
     
3 August 1899, Syracuse (NY) Post-Standard, pg. 2, col. 5:
Bids for Privileges
at the
State Fair, Sept. 4-9
(...)
These privileges include Dining Hall, Oysters, Cigars and Tobacco, Carbonaceotis and other soft drinks, Peanuts, Popcorn, Fruit, Coney Islands, Ice Cream, Candy, etc.
     
2 September 1900, Davenport (Iowa) Daily Leader, pg. 9, col. 4:
There were Coney Island red-hot men, “moochers,” “lifters,” and every other kind found on a race track.
   
19 October 1903, Albuquerque (NM) Morning Journal, pg. 2, col. 3:
The chile wagons coined money and the street vendors who dispensed Coney Island red hots and sandwiches were besieged by hungry throngs of New Mexicans.
 
24 March 1909, Syracuse (NY) Herald, pg. 7:
The State Fair commission to-day awarded…hot coneys and frankfurters to J. R. McCosker at $1,485.50.
       
27 August 1910, Syracuse (NY) Post-Standard, pg. 5, col. 1 ad:
WESTERN MEATS
(...)
Best frankfurts 12c
Coney Islands 13c
 
6 August 1911, Syracuse (NY) Herald, pg. C3:
Added to these features are stands where candy, soft drinks and “coney islands” can be purchased.
 
26 February 1915, Syracuse (NY) Herald, pg. 1, col. 2:
Frankforts 15c
Coneys 16c
     
10 September 1954, Sheboygan (WI) Press, pg. 11, col. 2 ad:
That Good
REED & BELL
Root Beer
CONEY DOGS
BARB-B-QUE BEEF
REED & BELL
DRIVE-IN
 
6 May 1957, Vidette-Messenger (Valparaiso, IN), pg. 3 ad:
Stop in for our
BIG CONEY DOG SPECIAL
(...)
DOG ‘n’ SUDS DRIVE-IN