White Castle is an American regional fast food hamburger restaurant chain located in the Midwestern and Mid-Atlantic United States, generally credited as the first fast food chain in the US. It is known for its small, square hamburgers. Sometimes referred to as "sliders", the burgers were priced at five cents until the 1940s, and remained at ten cents for years thereafter. For several years, when the original burgers sold for five cents, White Castle periodically ran promotional ads in local newspapers which contained coupons offering five burgers for ten cents, takeout only.

Official website: http://www.whitecastle.com