From 1972 to 1976, she narrated The Adventures of Letterman, an animated segment for The Electric Company.In 1973, Rivers wrote the made-for-television movie The Girl Most Likely to..., a black comedy starring Stockard Channing as an ugly girl who becomes beautiful after undergoing plastic surgery, and takes revenge of people who previously mistreated her.Following this appeareance, she became a frequent guest on the program and a close friend of Carson.As her profile raised significantly in the subsequent years, she started to make guest-appearances in numerous popular shows, including The Ed Sullivan Show, The Mike Douglas Show, The Dick Cavett Show and Girl Talk, with Virginia Graham. She had a brief role in the cult drama film The Swimmer (1968), starring Burt Lancaster, and at the time, she also had a short-lived syndicated daytime talk show, That Show with Joan Rivers, which premiered on September 16, 1968.Each episode had a theme and Rivers did an opening monologue based on the day's topic.
The soon-to-launch Fox Television Network announced that it was giving her a late night talk show, The Late Show Starring Joan Rivers, making Rivers the first woman to have her own late-night talk show on a major network. Carson learned of the show from Fox and not from Rivers.The new network planned to broadcast the show 11 p.m. In the documentary, Johnny Carson: King of Late Night, Rivers said she only called Carson to discuss the matter after learning he may have already heard about it and that he immediately hung up on her.In the same interview, she said that she later came to believe that maybe she should have asked for his blessing before taking the job.It ran for only nine performance amid a negative critical reception.Though a New York Times reviewer criticized the production as "frenetic to the point of being frazzled", he praised Rivers as "a deft comedy writer" and "a very funny lady".