The Big Mac became a major McDonald's brand symbol after its national introduction in 1968.
The sandwich was created by franchisee Jim Delligatti, who operated McDonald's restaurants in the Pittsburgh area. It used two beef patties, a middle bun section, lettuce, cheese, pickles, onions, and the signature sauce associated with the product.
The Big Mac had been tested regionally before McDonald's introduced it across the United States in 1968. Its name and distinctive three-part bun gave the menu item a strong identity separate from the general McDonald's brand.
The Big Mac is sometimes confused with the Quarter Pounder, another major McDonald's product, but the two were built around different product ideas. The Quarter Pounder emphasized the size of one beef patty; the Big Mac emphasized its layered construction and special sauce.