The 1970–71 season failed to gain a top 30 Nielson placing and the show was cancelled in 1971 after 274 episodes. The CBS network, prompted by pressure from advertisers seeking a more sophisticated urban audience, decided to refocus its schedule on several "hip" new urban-themed shows and, to make room for them, all of CBS's rural-themed comedies were simultaneously cancelled, despite some considerable Nielsen ratings. This action came to be known as "the Rural Purge." Pat Buttram, who played Mr Haney on Green Acres, famously remarked that, "It was the year CBS killed everything with a tree in it."
In addition to The Beverly Hillbillies, the series that were eliminated included Green Acres, Mayberry R.F.D., and Hee Haw, the last of which was resurrected in first-run syndication, where it ran for another twenty-one years. Petticoat Junction had been canceled a year earlier due to declining ratings following the death of its star, Bea Benaderet.
Read more about this topic: The Beverly Hillbillies