The Big Mac became a major part of McDonald's brand identity after its national launch in 1968.
Franchisee Jim Delligatti created the sandwich in the late 1960s for the Pittsburgh area. It used two beef patties, a special sauce, lettuce, cheese, pickles, onions, and a three-part sesame-seed bun, giving McDonald's a distinctive flagship product.
The sandwich was introduced nationally in the United States in 1968. Its name, layered construction, and later advertising made it more than a menu item: it became one of the clearest food symbols associated with McDonald's.
The Big Mac is sometimes confused with the Quarter Pounder because both are signature McDonald's hamburgers. The Quarter Pounder is defined by its quarter-pound beef patty before cooking, whereas the Big Mac is known for its two patties and middle bun section.