The Big Mac, introduced nationally in 1968, became one of McDonald's signature brand symbols.
Jim Delligatti, a McDonald's franchisee in the Pittsburgh area, created the sandwich after seeking a larger menu item for adult customers. It used two beef patties, a middle bun section, lettuce, cheese, pickles, onions, and the sauce later associated with the product.
The sandwich had been tested in the Pittsburgh market before its national introduction. Its distinctive three-part bun and layered construction helped separate it from simpler hamburgers and gave McDonald's a product with strong visual identity.
The Big Mac is sometimes confused with the Quarter Pounder because both became major McDonald's menu names. The Quarter Pounder was introduced later, in 1971, while the Big Mac's national launch was in 1968.