The Big Mac became a major McDonald's brand after its national introduction in 1968.
Jim Delligatti, a McDonald's franchisee in the Pittsburgh area, created the sandwich after experimenting with a larger hamburger format. The product used two beef patties, a middle bun section, lettuce, cheese, pickles, onions, and the sauce commonly associated with the Big Mac. It was first sold in the Pittsburgh area before McDonald's expanded it nationally.
The Big Mac gave McDonald's a highly recognizable signature product whose name and layered appearance were easy to advertise. Its packaging and promotional imagery helped make it more than a menu item: it became a durable part of the company's product branding.
The Big Mac is often confused with the Quarter Pounder because both became famous McDonald's hamburgers. The Quarter Pounder is defined by its patty weight before cooking, while the Big Mac is identified by its two-patty, three-part bun design.