Dick and Mac McDonald opened the first McDonald's restaurant in San Bernardino, California, in 1940.
The brothers began with a drive-in restaurant called McDonald's Bar-B-Q, which served a broad menu and relied heavily on carhop service. In 1948, they reorganized the business around a smaller menu and faster counter service, creating the foundation of the later McDonald's brand.
The original 1940 restaurant was not the familiar modern McDonald's. Its famous Golden Arches identity came later, after the brothers developed their Speedee Service System and Ray Kroc expanded the concept nationally. The San Bernardino site is therefore the starting point for the company, while the first restaurant opened by the McDonald’s System, Inc. corporation came much later in Des Plaines, Illinois.
A common mix-up is treating 1955 as the founding year. That was the year Ray Kroc opened the first restaurant operated by the corporation he established, not the year the McDonald brothers first opened a restaurant.