There's some debate over the origins of the modern sandwich, but the best known story is this: in the 1760's, John Montagu, the Earl of Sandwich, didn't want to leave the poker table, so he had somebody bring him some meat between two slices of toast. It caught on, and everybody called it "The Sandwich" after the guy who came up with it. We recreated the original sandwich the way Montagu would have had his: salt beef* on toast, nothing else.
To read the rest of the story, please go to: NPR.