Luis Ballast, owner of the Humpty Dumpty drive-in restaurant in Denver, Colorado, made an attempt to create a cheeseburger with a registered trademark known as a "yellowburger" in 1935.
Luís Ballast, propietario do restaurante drive-in denominado Humpty Dumpty en Denver (Colorado) no ano 1935, fai un intento de facer a marca rexistrada da cheeseburger denominada yellowburger («hamburguesa amarela»).