The 162-game schedule began in 1961 with the American League and extended to the National League in 1962.

During 1961 and 1962, baseball began adding and modifying multiple franchises, including the Minnisota Twins (1961, previously the Washington Senators), the new Washington Senators (eventually becoming the Texas Rangers), the Houston Colt .45s (eventually renamed to Houston Astros), and the New York Mets. The expanded schedule was designed to accommodate these franchise changes. The previous schedule had 154 games.