The Big Mac was introduced nationally by McDonald's in 1968 after a 1967 regional test.
Franchisee Jim Delligatti created the sandwich in western Pennsylvania because he wanted a larger burger for customers seeking a more substantial meal. Its distinctive construction used two beef patties, a middle bun section, lettuce, cheese, pickles, onions, and Big Mac sauce.
The sandwich was first tested in the Pittsburgh area in 1967 and then added to McDonald's menus across the United States in 1968. Its name became a major part of McDonald's product branding and later spread internationally.
The Big Mac is sometimes confused with the Quarter Pounder because both became signature McDonald's products. The Quarter Pounder is defined by the weight of its beef patty before cooking, while the Big Mac is defined by its two-patty, three-part-bun design.