Mayberry R.F.D. (R.F.D stands for "Rural Free Delivery", a quaint postal depiction of the rural Mayberry community) is a spin-off and direct continuation of The Andy Griffith Show under a new title, for the same sponsor, General Foods. When Andy Griffith decided to leave his series, most of the supporting characters returned for the new program, which ran for three seasons (78 episodes) on the CBS Television Network from 1968-1971. During the final season of The Andy Griffith Show, widower farmer Sam Jones (Ken Berry) and his young son Mike (Buddy Foster) are introduced and gradually become the show's focus. Sheriff Andy Taylor takes a backseat in the storylines- thus establishing the sequel series. The show's first episode, Andy and Helen's wedding, had the highest ratings in recorded television history (up to premiere date in 1968). Sheriff Taylor and newlywed wife Helen make guest appearances on RFD until late 1969, and are then written out. Mayberry RFD was popular throughout its entire run, but was canceled in CBS's infamous "rural purge" of 1971.