The Big Mac became the first McDonald’s national-menu item to use a three-part sesame-seed bun.
Franchisee Jim Delligatti created the sandwich in 1967 at his McDonald’s restaurants in the Pittsburgh area. Its distinctive middle bun allowed the larger sandwich to hold two beef patties, special sauce, lettuce, cheese, pickles, and onions. McDonald’s made the Big Mac available nationally in 1968, turning it into a major product symbol for the brand.
The Big Mac is sometimes described as having two buns, but its structure includes a separate middle section between the patties. That unusual construction became central to its visual identity and helped distinguish it from the standard hamburger and cheeseburger.