The origins and history of the hamburger is ambiguous to say the least. In the USA there are three claimants to the hamburger throne: Louis Lassen in 1900, "Hamburger Charlie" Nagreen in 1885, and the Menches Brothers - also in 1885.
However, there is one rather unusual claim that the Mongols, under the rule of Kublai Khan, would place meat in between themselves and the saddles of the horses they rode to tenderise it to the point where it could be eaten raw. The Mongols bought this idea with them to Russia and it later evolved into Steak Tartare.
Later, as a result of global trade, ships would dock into the port city of Hamburg, Germany and the Deutschvolk would mould and shape the meat into a steak shape and cook it and this became known as "Hamburg Steak".
However, back to the American claims. The burger chain "Louis' Lunch", which is based in New Haven, Connecticut claims the invention saying: "One day in the year 1900 a man dashed into a small New Haven luncheonette and asked for a quick meal that he could eat on the run. Louis Lassen, the establishment's owner, hurriedly sandwiched a broiled beef patty between two slices of bread and sen the customer on his way, so the story goes, with America's first hamburger."
The next claimant has a worryingly similar story. In 1885, "Hamburger Charlie" Nagreen apparently started selling meatballs at a summer fair and had a epiphany by inserting them in between pieces of bread, thus making it much more transportable. He, in fact, was the first to refer to it as the "hamburger", so this is possibly technically the correct "inventor".
In Ohio there is a chain of hamburger bars called Menches Bros. This family business is operated by the great grandchildren of Charles and Frank Menches, who claim invented the hamburger in 1885 at a fair in Hamburg, New York. One of the descendants, John Menches said in an interview, "Faced with nothing to sell at all, they fried [the ground beef] up, but it was too bland. My grandfather decided to put coffee, brown sugar, and some other household ingredients in it and cooked up the sandwich. My great-uncle Frank served the first sandwich, a gentleman tasted it and said, 'What do you call it?' Uncle Frank didn't really know what to call it, so he looked up and saw the banner for the Hamburg fair and said, 'This is the hamburger.' "
