Burgers
Big Mac
Two all-beef patties and a sauce that became a slogan.
A double-decker hamburger with a third bun slice in the middle, invented by Pittsburgh-area franchisee Jim Delligatti in 1967 and rolled out nationally in the United States the following year.
Jim Delligatti ran several McDonald's restaurants around Pittsburgh and wanted a larger sandwich for adult customers. Head office resisted; the chain's whole logic was a short menu that could be assembled in seconds. Delligatti got permission to test it in one Uniontown, Pennsylvania restaurant in 1967.
It sold. The Big Mac went nationwide in 1968 and became the reference product for the entire company, to the point that The Economist has used its price in different countries as an informal purchasing-power index since 1986.
The middle bun
The third bun slice is the sandwich's real engineering. It keeps a two-patty burger structurally stable and gives the sauce a second surface to sit on, which is why the build order is fixed in every kitchen manual.