What 1948 McDonald's innovation became the basis of its fast-food brand identity?

The Speedee Service System was the 1948 McDonald's innovation that became the basis of its fast-food brand identity.

The McDonald brothers redesigned their San Bernardino restaurant around speed, consistency, and a limited menu. They replaced much of the traditional drive-in model with a self-service format and organized food preparation in a way that resembled an assembly line.

This system made it possible to serve familiar items quickly and with similar results from one order to the next. That consistency later became essential to McDonald's expansion, because customers could recognize the experience even when visiting a different restaurant.

The system's name is sometimes confused with Speedee, the mascot used in early branding. Speedee was the character; the Speedee Service System was the restaurant operating method. Both names came from the same emphasis on fast service.