The Big Mac was introduced nationally across the United States in 1968.
Jim Delligatti, a McDonald's franchisee in the Pittsburgh area, created the sandwich after experimenting with a larger hamburger. The Big Mac used two beef patties, a middle bun layer, lettuce, cheese, pickles, onions and special sauce.
It first appeared in selected markets before receiving a nationwide U.S. rollout in 1968. Its distinctive three-part bun and layered construction made it especially useful as a branded product, not merely another hamburger on the menu.
The Quarter Pounder is a common mix-up because it also became a major McDonald's burger. The Quarter Pounder was introduced in 1971, while the Big Mac's nationwide launch came three years earlier.