McDonald's officially became simply McDonald's in 1948, after the original restaurant dropped “Bar-B-Q” from its name.
The first McDonald's restaurant opened in San Bernardino, California, in 1940 as “McDonald's Bar-B-Q.” Maurice and Richard McDonald initially operated a barbecue restaurant with a broad menu. In 1948, they closed temporarily, redesigned the operation around a limited hamburger menu, and reopened under the shorter McDonald's name.
This change accompanied a major shift in the restaurant's identity. The brothers emphasized hamburgers, fries, milkshakes, speed, and self-service rather than barbecue. The later corporate brand developed from this simplified restaurant model, although the famous Golden Arches logo came afterward.
A common mix-up is treating 1948 as the founding year. McDonald's began in 1940; 1948 marks the reopening and name change that established the streamlined hamburger concept.