Burgers were first popularized in the U.S. by German immigrants settling around Cincinnati. But the first hamburger wasn't eaten between the halves of a bun until the early 1900s. The sandwich, meat of any kind placed between two slices of bread, has been with us since the 18th century – apparently, the sandwich was invented by a gambler named John Montagu, the fourth earl of Sandwich, who stuffed his meat between bread slices so that he could eat right at the gambling table. Officially, the first “hamburger” sandwich appeared at the 1904 Louisiana Purchase Exposition in St. Louis, Missouri (which also happens to be the birthplace of the ice-cream cone).