McDonald's introduced the Big Mac in 1967.
The sandwich was created by Jim Delligatti, a McDonald's franchisee in the Pittsburgh area. It used two beef patties, a middle bun section, lettuce, cheese, pickles, onions, and a special sauce. Its distinctive three-part bun and memorable name gave McDonald's a flagship product that could be marketed as a recognizable brand within the wider restaurant brand.
The Big Mac initially appeared in the Pittsburgh area before McDonald's made it available nationally in the United States in 1968. That one-year distinction explains why sources may mention both 1967 and 1968: 1967 refers to the original introduction, while 1968 refers to national rollout.
The Big Mac later became an international reference point for comparing food prices. The Economist's informal Big Mac Index, launched in 1986, uses the sandwich to illustrate purchasing-power differences between currencies.