The Big Mac, introduced in 1968, became McDonald's signature premium burger.
Franchisee Jim Delligatti created the sandwich in the Pittsburgh area. He wanted a larger burger that could compete with the substantial sandwiches offered by rival fast-food restaurants. The sandwich used two beef patties, a middle bun layer, lettuce, cheese, pickles, onions, and the sauce later associated with the Big Mac.
McDonald's introduced the product nationally in 1968. Its unusual three-part bun and distinctive name made it easy to recognize in advertising and helped turn it into a major branding asset rather than merely another menu item.
The Big Mac is sometimes confused with the Quarter Pounder. The Quarter Pounder was introduced earlier, in 1971 according to McDonald's history commonly cited for the product, while the Big Mac dates to 1968. The Big Mac's defining structural feature is its middle bun layer.