Small greasy hamburgers (round or square) topped with fried onions (sliced stringy or chopped minced) and thin sour dill pickles. Mustard, ketchup, and cheese is optional. They are most commonly sold at small white
ceramic tiled diners, often with a castle design, an Art Deco design, or 50's malt shop design. The most famous and most commercially successful sliders were made by White Castle Hamburgers. Their sliders are square in shape. With 5 holes took out the very thin patty. They are not as good as sliders from the Independant places, but they are cheaper.
Bray's,
Greene's, Tel Way, Hunter, Bates, White Way, Top Hat, And Comet are a few of the Independant slider restaurants that exist or has existed.