Whatever the case, beef was a rare treat in early urban America. Pork was the meat of choice, because it could be preserved in a variety of tasty ways. Bacon will always win out over beef jerky. The first revolution in hamburger history arrived in the second half of the 19th century. With the pioneer movement westward, the grasslands of the Great Plains were opened up to cattle-grazing. Mythmaking cowboys herded the steers to the railheads of the huge new railroad network that strapped the nation together. Chicago became the world’s biggest slaughterhouse, and refrigerated cars carried the meat into the heart of every American city. Suddenly, red-blooded beef was available to every red-blooded American.

So who flipped the first hamburger? The residents of St Louis claim that the first burger was cooked at the 1904 World’s Fair and the city recently celebrated a hamburger cent­enary. Not so, says Seymour, Wisconsin. Charlie Nagreen did it in 1885, and, to solidify the claim, Seymour opened the Hamburger Hall of Fame in 1990 (a must-see for any foreign visitor). But, then, Lou’s Lunch in New Haven, Connecticut, has been shovelling hamburgers into the mouths of Yale students since 1895. Who to believe?

It doesn’t matter, writes Ozersky, because all of these were faux-burgers. They were served on slices of bread, not on a bun. And the bun is the essential, distinguishing basement and roof of hamburger architecture, because a) it provides a firm, crusty encasement to absorb the juice of the meat without going gooey; b) it consequently allows the diner to eat the thing with bare hands; and c) it thus liberates the diner to indulge that most American of American characteristics: mobility. The true hamburger, Ozersky concludes, is “as artfully self-contained as a Homeric hexameter”.