Where does the hamburger come from?

Hamburg steak and its various national adaptations may be the forebears of the modern hamburger. This steak was first documented in 1884 in the United States, and in Hamburg, Germany, in 1885, where it was originally known as "Rundstück warm" ("round piece, warm")—a sliced roll (Rundstück) with a hot meat patty stuffed in between (warm). Although Hamburg steaks existed by the early 1800s, they did not have a bun; it wasn't until 1885 at Louis' Lunch in New Haven, Connecticut, that a patty of minced beefsteak was placed between two pieces of bread. Other claims to have invented the hamburger include Hamburg native Otto Kuase in Seymour, Wisconsin, in 1895, and Charlie Nagreen during the 1904 St. Louis World's Fair. There are two schools of thought on the origin of the hamburger: the "Germany school" and the "America school". The Germany school holds that the hamburger originated in Hamburg, Germany, while the America school holds that it originated in the United States. There is no definitive proof to support either claim, and the origin of the hamburger remains a matter of debate.