A hamburger (or burger) is a sandwich consisting of a cooked ground meat patty, usually beef, placed in a sliced bun or between pieces of bread or toast. Hamburgers are often served with various condiments, such as ketchup, mustard, mayonnaise, relish etc. as well as lettuce, tomato, onion, pickles, and cheese.

It is believed that the idea for a hamburger occured in 1885 when Frank and Charles Menches, created it at the Buffalo Fair in Hamburg, New York. The hamburger, as the story goes, was born when the brothers ran out of sausage for their regular sandwich. The name of the Hamburger came from the idea of "Hamburg steak", or ground beef.

Charles "Hamburger Charlie" Nagreen was also an American claimant to the title of inventor of the hamburger. Nagreen was a vendor at the 1885 Seymour Fair.After not experiencing success selling meatballs, he had an idea to smash a meatball and placed it between two slices of bread. His idea was a success and he returned every year until his death in 1951.