From Ohio History Central
It remains unclear, but some historians claim that Canton, Ohio, residents Frank and Robert Menches invented the hamburger. In 1885, these two brothers were selling pork sandwiches at the Erie Agricultural Fair in Hamburg, New York. Supposedly, the brothers ran out of pork and could not find a butcher willing to slaughter a pig. The two men proceeded to purchase five pounds of beef, ground the beef up, and then mixed several items, including coffee and brown sugar, into the meat. The Menches brothers supposedly named their sandwich after the town where they first served the product. Demand purportedly was so high that the two men continued to travel from fair to fair, selling their hamburgers.
In 1991, descendants of the Menches brothers discovered a copy of the original recipe. They began selling the original hamburgers at fairs, just like their ancestors had done. Today, they also sell the hamburgers, known as Menches Gourmet Burgers, in grocery stores. The company is located in Green, Ohio. They also have sold the hamburgers on QVC, a television shopping channel.