Was the hamburger birthplace at the Seymour Fair in Wisconsin?

Charlie Nagreen sold a meatball between two slices of bread at the Seymour Fair in 1885. (Outagamie County Fair)

The Seymour Community Historical Society of Seymour, Wisconsin, claims that Hamburger Charlie (Nagreen) invented the hamburger. That is one of the earliest claims to the invention of hamburgers. The Seymour Historical Society says that Nagreen’s hamburger’s namesake was none other than the area’s German immigrants’ Hamburg steak. However Hamburger Charlie’s sandwiches were made of pork.

Charlie Nagreen was only fifteen years old when he was peddling his hamburgers at the 1885 Seymour Fair. It is claimed that he made the hamburger sandwiches so that customers could eat while walking through the fair grounds.