Mayberry R.F.D.
Producers called the last episode of The Andy Griffith Show, which aired September 23, 1968, “Mayberry R.F.D.” Those letters, R.F.D. stood for Rural Free Delivery. That became the launchpad for a spin-off show by the same name later that year. Mayberry R.F.D. aired from 1968 to 1971.