McDonald's introduced the McDonaldland advertising universe in 1971. The campaign created a recurring fantasy setting in which the company's mascots and menu-related characters could interact.
Ronald McDonald served as the central figure, joined by characters such as Mayor McCheese, the Hamburglar, Officer Big Mac, and Grimace. The characters appeared in television commercials and other promotional material, giving McDonald's a distinctive family-oriented storytelling system.
McDonaldland was part of a wider shift toward recognizable brand characters in children's advertising. Its setting made individual restaurant products easier to remember by linking them to names, personalities, and visual designs.
The cast was not completely fixed. Some characters were redesigned, retired, or used less frequently as advertising priorities changed. That evolution can make dates seem inconsistent, but the advertising universe itself is generally dated to 1971. Ronald McDonald's earlier debut in 1963 was a separate milestone.