The Big Mac became a major McDonald's brand symbol after its 1968 national debut.
Jim Delligatti, a McDonald's franchisee in the Pittsburgh area, developed the sandwich as a larger alternative to the chain's standard hamburgers. It used two beef patties, a middle bun section, lettuce, cheese, pickles, onions, and the sauce commonly associated with the Big Mac. McDonald's introduced it nationally in 1968 after regional testing.
The sandwich quickly became more than a menu item. Its distinctive three-part bun and memorable advertising helped make it an international symbol of McDonald's. The Big Mac Index, created by The Economist in 1986, later used the burger as an informal way to compare purchasing power between currencies.
The 1968 date refers to the national launch, not the first local test. The sandwich had already been sold in Delligatti's region before the wider rollout. It is also distinct from the Quarter Pounder, which uses a different patty format and became nationally available earlier.