Who invented the hamburger? This seemingly simple food item, perhaps the world's most popular snack, has a surprisingly murky history.
Hamburg is a medium sized port in the north of Germany, on the Elbe River.
The location makes the city open to outside influences. It is a busy trading centre, close to eastern Europe and Scandinavia, and visiting merchants bring new ideas, products, and customs.
Somewhere in the mid 18th century, when precisely is not known, bustling Hamburg saw the arrival of a new culinary concept; diced beef steak, mixed with egg, onion and spices, formed into flattened disks and fried.
The dish may have arrived in Hamburg via English sailors, or Russian merchants.
Both countries had dishes that were similar, and had significant trade with Germany. But wherever the recipe originated, it quickly caught on in the city, and then spread throughout the country.
Served with roast vegetables, or salad, the 'Hamburg Steak' quickly became a staple of the German diet. It was simple to prepare, cheap and tasty, and versatile.
As its popularity grew, Germany would export the idea to the world.
As the 19th century unfolded, waves of immigrants fanned out from Europe, looking for fresh opportunity elsewhere. Many of these headed for America, then still establishing itself as a world power.
Hard working, diligent and socially conservative, German migrants settled in the United States in large numbers, and many of them prospered.
They brought their cultural traditions with them, and the Hamburg Steak had a vast new market. The first recorded reference in America is from the 1870s:
'A 'Hamburg Steak' is simply a beef-steak, redeemed from its original roughness by being mashed into mincemeat, and then formed into a conglomerated mass, and fried.'
- 'The New York Times', 1873
The dish again proved popular. By the 1880s, Hamburg Steaks were well established on the east coast of America, and could be found on the menu of most diners and cafes.
But, something strange was happening to the name; it had somehow gone from 'Hamburg', to 'Hamburger':
'Those flat, brown, meat cakes on that dish there are Hamburg Steaks; the people call them 'Hamburgers.' They are made from raw meat chopped up with onions, and spices, and are very good.'
- 'The New York Sun', 1883
No one really knows why, beyond people's natural inclination to play with words.
The hamburger pattie in America in the 1880 looked and tasted much like it does today. But it remained something that you sat down to eat on a plate, with a knife and fork and some sides.
Who was the innovator that turned it into a sandwich? Our first contender is Charlie Nagreen.
Born into a poor family in Hortonville, Wisconsin in 1870, Nagreen left school at an early age, and made a living with a mobile lunch cart. He used a small gas grill to heat and serve meatballs, and was undoubtedly familiar with Hamburg Steaks; Wisconsin had a substantial German population.
In October 1885, Nagreen used a team of oxen to drag his lunch cart 20 miles to the nearby town of Seymour, and set up his cart at the town fair. While there were plenty of potential customers, there was also a problem: everyone wanted a snack they could take with them.
The meatballs Nagreen was selling did not suit the crowd, who wanted to see the attractions while they ate.
The resourceful young entrepreneur hit on an ingenious solution. He bought a few loaves of bread from a sandwich stand, flattened his meatballs into patties, and served them between two slices of bread so they could be carried.
This creation was a success, and Nagreen made a tidy sum. He trialled his new sandwich at other events, and it proved so popular that he soon made them his primary product, and sold them at fairs all across Wisconsin.
Nagreen became known as 'Hamburger Charlie'. And as the food item became more widespread, he also promoted the claim that he was its inventor.
But while Hamburger Charlie's story is mostly verifiable his role as the hamburger's inventor is not.
While the claim is repeated on numerous websites, including Wikipedia, no tangible evidence is available to confirm that Charlie was even at the Seymour State Fair in 1885, let alone selling hamburgers there. His claim is strong, but Charlie may have been an early adopter, rather than an inventor.
Frank and Robert Mench also operated a travelling snack stand, selling sliced pork sandwiches at fairs and public events.
In either 1885, or 1892 (different versions have different dates) the brothers set up shop at the county fair in Akon, Ohio, and would later claim to have invented the hamburger there.
Having run out of pork due to unexpectedly high demand, the brothers tried to source more meat from a local butcher. But the popularity of the fair meant that supplies were short, and all the Mench's could get their hands on was five pounds of ground beef.
They used this to prepare a batch of Hamburg Steaks, also well known by this time in Ohio. To serve them, they employed the remainder of their sandwich making supplies; bread, and salad, with a ground beef pattie in between.
A modern style hamburger was produced.
But the problem with this origin story, plausible though it sounds, is the same as Hamburger Charlie's; there is no evidence beyond the brother's claims that it ever happened.
The Mench's ran a mobile sandwich stand, that later became a bricks-and-mortar shop. But there are no newspaper reports of them serving hamburgers in 1885 or 1892, and no mention of them having invented hamburgers until much later.
As a footnote, in the modern era 'Mench Bros' is a small goods company, that specialises in frozen hamburger patties.
Another claimant is Fletcher 'Old Dave' Davis, who ran a small diner in the Texas city of Athens, just outside Dallas.
Sometime between 1896 and 1900 (accounts vary), Davis came up with a version of the hamburger; a ground beef patty, served between two slices of thick, crusty bread called Texas Toast.
While Davis did not call his sandwich a 'hamburger', it was a popular and well known local lunch item, and several residents have left behind first hand accounts of eating it at his restaurant.
Davis' sandwich was so popular, in fact, that he was invited to the World's Fair in St Louis in 1904, where he cooked them in the food hall. The large audience at this event, and the favourable response the sandwich received, meant that many visitors took the idea back home with them.
Davis' efforts helped popularise hamburgers, across America.
But his role as their inventor is not possible; by 1896, there are recorded reports of hamburgers already in the American media. This did not stop Davis from claiming to be the inventor, and labelling his Texas establishment as 'the birthplace of the hamburger'.
In 1893, the Evening Gazette in Reno, Nevada, carried an article that made specific mention of 'hamburger steak sandwiches' that were sold in a local cafe.
By the following year, the Los Angeles Times had a description of the same thing being sold by street vendors in LA. The casual nature of both of these references indicates that hamburgers - beef patties between two pieces of bread - were already well known in both places by this time.
Which brings us back to the beginning.
Who invented the hamburger? It is probably impossible to determine.
And another, less satisfying, explanation is that there is no individual creator , but rather a series of innovations, over period of time.