How was the first cheeseburger made?

The cheeseburger was invented in 1924 by Lionel Sternberger at The Rite Spot in Pasadena, California. While running low on hamburgers one day, Mr. Sternberger purchased some sliced American cheese from a nearby grocery store and placed it on top of the hamburgers that he still had. Mr. Sternberger and his customers both enjoyed the taste, and the cheeseburger was soon on the menu.

In 1926, Louis Lassen, owner of The Humpty Dumpty Drive-In restaurant in Denver, Colorado, popularized the cheeseburger.