Big Mac became a registered McDonald’s product trademark after the sandwich debuted in 1968.
The Big Mac had first been created and sold at a McDonald’s restaurant in 1967, then received a broader national launch in 1968. Its name, stacked construction, special sauce, and distinctive three-part bun made it especially useful as a branded menu icon rather than just another hamburger.
Trademark protection helped McDonald’s identify “Big Mac” as a specific company product. This is different from a generic description such as “double hamburger,” which can describe many sandwiches. The Big Mac’s name became recognizable internationally and was later used in advertising, packaging, merchandise, and comparisons of purchasing power.
The product is sometimes dated only to 1968, because that was the national rollout year. The earlier 1967 sale explains why sources may mention both years. The distinction between invention, test sale, and national introduction is important when tracing the sandwich’s branding history.