Originator: Maurice and Richard McDonald. Modified by Ray A. Kroc. Date of origin: 1948. Notes: The original McDonald hamburger patties were made 10 to the pound of beef. The Quarter Pounder, shown here, was introduced in 1971. Experiments were conducted to find the right wax paper to use between the patties. It has to be slick enough so the meat will pop onto the grill and not stick, but not so slick as to make handling difficult. McDonald's hamburgers are found in 6,000 outlets in 25 countries. By 1980, over 30 billion had been sold.