McDonald's first reached the milestone of one billion hamburgers served in 1963.
The milestone reflected the rapid expansion of the chain during the 1950s and early 1960s. Ray Kroc had begun developing the franchise system in the 1950s, and the number of McDonald's restaurants grew quickly across the United States. The company used the achievement in signs and advertising to demonstrate its popularity.
The phrase “Over 1 billion served” became closely associated with McDonald's branding. It was not a claim that every hamburger had been individually tracked; it was a cumulative promotional estimate used to communicate scale. Later versions of the sign updated the number as sales continued to rise.
The milestone is sometimes confused with the opening of the first Kroc-operated franchise in 1955 or the introduction of the Big Mac in 1967. Those are important dates, but the billion-hamburger figure belongs to 1963.