The Big Mac became the centerpiece of McDonald's national branding campaign after its 1968 introduction.
The sandwich was created by franchisee Jim Delligatti, who operated McDonald's restaurants in the Pittsburgh area. It used two beef patties, a middle piece of bread, lettuce, cheese, pickles, onions and sauce. The extra bread layer and distinctive construction helped separate it from the company's simpler hamburgers.
McDonald's tested the product regionally before introducing it nationally in 1968. Its name and unusual structure made it particularly suited to advertising, and the sandwich soon became one of the company's most recognizable menu brands.
The Big Mac is sometimes confused with the Quarter Pounder because both became major McDonald's signature sandwiches. The Quarter Pounder is identified by the weight of its beef patty, while the Big Mac is identified by its two-patty, three-bun construction.