The Big Mac became McDonald's signature burger after its national introduction in 1968.
The sandwich was created by Jim Delligatti, a McDonald's franchisee who operated restaurants in the Pittsburgh area. He developed a larger burger with two beef patties, a middle bun section, lettuce, cheese, pickles, onions, and the sauce now associated with the sandwich. McDonald's introduced the item nationally in 1968.
Its layered construction and distinctive name made the Big Mac unusually easy to recognize in advertising and popular culture. The product became more than a menu item: it served as a durable branding asset that could identify McDonald's even when the Golden Arches were not shown.
The Big Mac is sometimes confused with the Quarter Pounder because both became major McDonald's burgers. The Quarter Pounder is defined by its quarter-pound beef patty before cooking, while the Big Mac is defined by its two-patty, three-bun structure and special sauce. The Big Mac's 1968 national launch is the relevant branding milestone.