The Big Mac was McDonald's menu item built around special sauce, two beef patties, and a three-part bun.
Jim Delligatti, a McDonald's franchisee in Pennsylvania, created the sandwich in 1967. It was initially tested in the Pittsburgh area before McDonald's introduced it nationally in 1968.
The Big Mac's signature construction includes two all-beef patties, special sauce, lettuce, cheese, pickles, and onions on a sesame-seed bun with an extra middle section. Its distinctive layered shape made it particularly useful in McDonald's visual branding and advertising.
The Big Mac is sometimes confused with the Quarter Pounder, but the two sandwiches have different origins and constructions. The Quarter Pounder was introduced nationally in 1973 and is identified primarily by its larger single beef patty.