The Big Mac gave McDonald's its first nationally advertised signature sandwich.
Jim Delligatti, a McDonald's franchisee in Pennsylvania, created the sandwich in 1967. It used two beef patties, a middle bun layer, lettuce, cheese, pickles, onions, and sauce. McDonald's introduced it nationally in the United States in 1968.
The sandwich became more than a menu item: its name, layered construction, and special sauce gave McDonald's a powerful product identity that could be promoted across markets. The Big Mac's advertising helped establish a recognizable flagship product alongside the company's broader restaurant branding.
The Big Mac is sometimes confused with the Quarter Pounder because both became major McDonald's products. The Quarter Pounder is defined by the nominal weight of its beef patty before cooking, while the Big Mac is defined by its two-patty, three-bun construction.