Harry F. Duncan of Little Tavern claimed to have invented the cheeseburger in the 1920s, but I never put much faith in that claim. Many have made the same assertion with little proof, and it’s hard to imagine the concept of meat and cheese wouldn’t have been come up with independently in many places. Rite Spot of Pasadena claims 1926 with nothing to back up that date. O’Dell’s of Los Angeles claims 1928, though the menu they use as evidence dates to the 1930s. Kaelin’s of Louisville claims 1934.
Today I found the first actual proof, an ad from June of 1932 from Little Tavern, advertising the Cheeseburger (note that they have it listed as trademarked)as being exclusively available at Little Tavern. As far as I can tell, this is the first time the word was used in a newspaper. After this initial run of ads, Little Tavern never tried to capitalize or publicize their invention. It’s interesting in this 1932 ad that the cheeseburger is double the price of the standard hamburger.