A notable movement in US television around the turn of The '70s—"one of the earliest efforts at channel drift", according to That Other Wiki—when the AC Nielsen company made changes to give networks and advertisers a clearer picture of just who (as well as how many people) watched which shows. At the time, many popular programs (such as Green Acres and Hee Haw) were rural-themed and were skewing more towards viewers from rural areas or just an older demographic in general. By contrast, younger "urban" viewers wanted more contemporary and innovative programs. In addition, the FCC's new "Prime Time Access Rule" came into effect for the 1971-72 season, which forbade networks from scheduling programming in the 7:00 p.m. ET/PT hour (a move intended to help spur the syndication market, alongside the concurrent "FinSyn" rules that effectively required the networks to divest their syndication divisions), forcing the traditional start of primetime to move from 7:30 p.m. to 8:00 p.m.
The purge began in 1970 with the cancellation of Petticoat Junction by CBS; to be fair, the series' viewership had been declining since the death of its star Bea Benaderet. CBS was by far the biggest offender in the purge, cancelling a large array of Long Runners just because they skewed too old. Actor Pat Buttram of Green Acres (which, unsurprisingly, got canned) famously commented that CBS "canceled every show that had a tree in it— including Lassie."
Despite its name, the resulting carnage was not exclusively aimed towards rural shows; the casualties of the purge included several long-running westerns (including Bonanza, though the genre had been in a decline due to Moral Guardians complaining about their violence, and Bonanza itself was facing declining ratings due to the death of co-star Dan Blocker) and variety shows, such as The Jackie Gleason Show, The Lawrence Welk Show, and The Red Skelton Show. CBS and ABC each also killed two birds with one stone by cancelling the rural variety shows Hee Haw and The Johnny Cash Show.
Several of the variety shows were promptly Un-Canceled: Red Skelton got saved for one more season by NBC, while The Lawrence Welk Show and Hee Haw successfully moved to syndication — lasting all the way through 1982 and 1992 respectively. Country singer and Hee Haw personality Roy Clark ultimately recorded a song, "The Lawrence Welk-Hee Haw Counter-Revolution Polka", acknowledging these events as a Take That! against the Rural Purge. For most of the scripted shows, though, the rural purge was a mercy killing of near-Zombie Franchise shows that either were going on with major original cast members having left or had worn out their premises (one can only be a Fish out of Water for so long...), Vindicated by History in that the bulk of them are far more popular today in their earlier black-and-white seasons and seldom seen in the late seasons from the last few years before the ax.
Ironically, the biggest subversion of the purge was the 1972 CBS rural drama The Waltons. It is said that, in response to Congressional hearings on the quality of TV programming following the purge (including, in particular, fewer programs targeting family viewing), CBS deliberately slotted The Waltons against the popular Thursday-night programs The Mod Squad on ABC and The Flip Wilson Show on NBC) under the presumption that it would fail, and CBS could say there was no interest in such programs. In reality, it was a critical and ratings success, lasting nine seasons, peaking as the second-highest rated program on television in its second season, and launching the successful Lorimar studio.
It should be noted that had Nielsen's finer-grained information become available a few years earlier, Star Trek: The Original Series and The Smothers Brothers Comedy Hour would no doubt have run longer; they attracted the well-educated younger viewers advertisers crave, but nobody knew it at the time and saw only mediocre total-viewership numbers for the former and the latter's battles with Executive Meddling would have been easier to endure if the network had the later audience priorities.
Some of the shows cancelled in the purge included:
- Mayberry R.F.D. (CBS, 196871)
- The Beverly Hillbillies (CBS, 196271)
- The Ed Sullivan Show (CBS, 194871)
- Green Acres (CBS, 196571)
- Hee Haw (CBS, 196971; revived in syndication, where it ran until 1992)
- The Virginian (NBC, 1962-1971)
- Bewitched (ABC, 1964-1972)
- I Dream of Jeannie (NBC, 1965-1970)
- Hogan's Heroes (CBS, 196571)
- My Three Sons (ABC, 1960-1965; CBS 1965-1972)
- American Scene Magazine / The Jackie Gleason Show (CBS, 196270)
- Family Affair (CBS, 1966-1973)
- The Johnny Cash Show (ABC, 196971)
- Lassie (CBS, 195471; moved to syndication, where it ran until 1973)
- The Lawrence Welk Show (ABC, 195571; moved to syndication, where it ran until 1982)
- Petticoat Junction (CBS, 196370)
- Mutual of Omaha's Wild Kingdom (NBC, 1963-1971, moved to syndication with new episodes produced until 1987)
- The Andy Williams Show (NBC, 1962-1971 followed by a brief run in syndication)
- The Red Skelton Show (CBS, 195370; moved to NBC, ending in 1971); it ranked #7 for the 1969-70 season, making it the highest-rated show ever to be cancelled in television history up to that point
Nonetheless, the purge set the stage for a number of new shows to be introduced to the network lineups, some of which became legendary on their own.
Some of the shows which the purge made room for included:
- Adam-12 (NBC, 1968-1975)
- All in the Family (CBS, 19711979)
- The Bob Newhart Show (CBS, 19721978)
- The Carol Burnett Show (CBS, 1967-1978)
- Charlie's Angels (ABC, 1976-1981)
- Eight is Enough (ABC, 1977-1981)
- Emergency! (NBC, 1972-1977)
- Good Times (CBS, 1974-1979)
- The Jeffersons (CBS, 1975-1985)
- Kojak (CBS, 1973-1978)
- The Love Boat (ABC, 1977-1986)
- M*A*S*H (CBS, 19721983)
- The Mary Tyler Moore Show (CBS, 19701977)
- Maude (CBS, 19721978)
- Police Story (NBC, 1973-1978)
- Quincy, M.E. (NBC, 1976-1983)
- The Rockford Files (NBC, 1974-1980)
- The Rookies (ABC, 1972-1976)
- Sanford and Son (NBC, 1972-1977)
- Starsky & Hutch (ABC, 1975-1979)
- Vega$ (ABC, 1978-1981)
- Welcome Back, Kotter (ABC, 1975-1979)