McDonald's introduced the Big Mac nationally in the United States in 1968.
The sandwich was created by Jim Delligatti, a McDonald's franchisee in the Pittsburgh area. Delligatti had already experimented with larger sandwiches before developing the Big Mac, which used two beef patties, a middle bun section, lettuce, cheese, pickles, onions, and sauce.
The Big Mac first appeared in selected restaurants before its national launch. Its distinctive two-layer structure and branded sauce helped make it one of McDonald's most recognizable menu items. The product name is often confused with the year of its first test sales, but 1968 is the key date for its national U.S. introduction.
McDonald's later used the Big Mac as a global brand symbol, including the Big Mac Index, an informal purchasing-power comparison created by The Economist in 1986.