White Castle

During my young adult days in the Detroit area, I drunkenly ate more White Castle hamburgers than my arteries care to remember. I never realized I was eating from history, until I saw this piece that claims WC blazed the path for McDonald's and Co. Excerpt:

White Castle did not invent the hamburger, [David] Hogan [author of White Castle and the Creation of American Food] writes, but made it palatable to Americans wary of ground meat in the age of Upton Sinclair's "The Jungle." White Castle co-founder Billy Ingram reassured customers that White Castle served quality burgers by situating grills in full view of customers; by stressing cleanliness and only hiring men with "high personal hygiene"; and by proving the nutritional value of the burgers through commissioned "studies." (In one, a student lived for 13 weeks on only White Castle burgers and water -- he ate about 20 burgers a day and thrived.)

Aside: White Castle hamburgers have five holes in them. An old joke ran, "You know why White Castle hamburgers have five holes in them? Because it takes five bullets to kill a rat."

(The real answer, incidentally, is, "To facilitate steaming."