The Big Mac gave McDonald's its famous two-beef-patty branded name in 1967.
McDonald's introduced the Big Mac in 1967 after franchisee Jim Delligatti developed the larger sandwich for customers seeking a more substantial meal. Its distinctive identity came from two beef patties, a middle bun layer, special sauce, lettuce, cheese, pickles, and onions.
The product was first sold in the United States and then became one of McDonald's most recognizable menu brands worldwide. The name is sometimes confused with the Quarter Pounder, another major McDonald's product, but the Big Mac's defining branding is its layered three-part bun and two-patty construction.
The Big Mac also became useful as a cultural and economic reference because economists created the informal “Big Mac Index” to compare purchasing power between currencies.