This isn’t about Colbert, Fallon and Kimmel. Or Conan or Seth or James or any current talk show host. It’s not even about Jay or Dave or Arsenio or Joan.
The war I’m talking about happened from 1967 to about 1975. Johnny Carson was king but he was challenged by Merv Griffin on CBS and Joey Bishop/Dick Cavett on ABC.
Back in 1967, Carson was still in New York and his show was 90 minutes long, having been actually 105 minutes. His show would permanently move to Los Angeles in 1972 and would shorten to 60 minutes in 1980. He not only outlasted, but crushed the competition. Carson gained ratings clout in the 1970s and became a huge profit center for NBC.
The Tonight Show began with Steve Allen in 1954, then Jack Parr took over in 1957, and tweaked Allen’s format to be generally what you see today. Carson followed in 1962.

The show was a mixture of comedy, light conversation with entertainers and sports figures, and more serious discussions with authors, politicians and academics. Late night was more than comedic chatter, world events and serious art were center stage and in your living room, or bedroom.
Other talk shows began to spring up, some locally, some network daytime and others in syndication. The most popular of these was Merv Griffin. Ironically, Griffin and Carson both started their shows in 1962, and both taped their shows daily in the same New York studio.

Meanwhile, ABC, the least successful of the three networks, brought in Rat Pack member, Joey Bishop, in 1967, with sidekick Regis Philbin (who?), to go head-to-head with Carson.
Bishop had been a frequent Carson guest and now was his competitor. Bishop and Carson went after a lot of the same guests, so it made Bishop’s show seem like a knockoff. In 1969, due to low ratings, ABC replaced Bishop with a younger, more urbane Dick Cavett, who had once been a Carson writer.

Merv Griffin’s show went through several iterations in syndicated, which allowed stations to air the show at various times, including up against Carson in some markets. In 1969, CBS came calling and put Griffin up against Carson. Griffin brought his announcer, actor and fish & chips restaurateur, Arthur Treacher.
Now, all three networks had a show in late night. Each show was generally the same: monologue or opening comments by the host; Hollywood and Broadway star; personality or comedian; arts or politician for the later segment. Late night covered a lot of ground.

Even Merv balanced the comedic with the serious, and the artsy. I recently found his syndicated show on Amazon Prime. As an example, an episode labeled September 2, 1965 had Phyllis Diller, Capt. Mitsuo Fuchida (Japanese Navy during WWII) and spy author Frederick Ayer, Jr., a former FBI agent and intelligence officer during WWII. Griffin interviewed Capt. Fuchida, who was part of the attack on Pearl Harbor, and Mr. Ayer who was part of a group that had credible intelligence about Japanese military plans. It wasn’t a great interview but it was very good, and it showed the kind of world events that balanced the lightheartedness of comedians.

In 1972, CBS pulled the plug on Griffin, and his show went back to syndication where it aired at a variety of times including as a late afternoon show like Mike Douglas and Dinah Shore. At the time, CBS had fewer affiliates than NBC, and in some markets, they hadn’t aired his show against Carson, so his ratings didn’t seriously challenge Carson.

Cavett, seemed to go after some of the hipper, more daring guests that Griffin sometimes booked. Although Cavett’s show would officially run till January 1975, ABC had reduced the show’s airing in 1973. By 1975, his show was only occasionally broadcast. Some of Cavett’s best shows were with musicians and actors who didn’t often appear on talk shows. It was not usual for Cavett to spend an entire show with someone like Groucho Marx, John Lennon, Katharine Hepburn or Orson Welles. If you wanted witty, daring conversation, Cavett was where you tuned in. Cavett went on to host a successful talk show on PBS.

Griffin, to the dismay of CBS, had gone that route as well, booking guests like Abbie Hoffman or Martin Luther King, Jr. Although he was an affable personality not known for controversy, Griffin didn’t shy away from guests who were, wanting to explore issues of interest to viewers. Griffin was the kind of host who put the focus on the guest, not on himself.
Carson survived the dual network threat and by 1973 was unchallenged in the late night talk show universe. In fact, NBC added The Tomorrow Show with radio/television personality Tom Snyder in 1973, which followed Carson nightly. Snyder lasted until the early 1980s, when David Letterman took over the time slot. Ironically, when Letterman left NBC for CBS, he later brought Snyder along to fill the time slot after his show, The Late Late Show, until 1999.

In the 1980s, late night was ready for more players again. Arsenio Hall got a talk show, as did Pat Sajak, Joan Rivers and eventually Chevy Chase and Magic Johnson, and many others. Everybody was jumping in and most of them failed. When Carson retired, the talk show world shook as Jay and Dave battled for the Tonight Show throne.
Merv Griffin continued in syndication until 1986 when he folded up his talk show and focused on his production company that included Jeopardy! and Wheel of Fortune eventually selling his production company for over $250 million. Merv did very well for himself and used part of his wealth to own a number of exclusive hotels. He was worth well over $1 billion when he died in 2007.

Joey Bishop went back to television, film and nightclubs, and once again became a guest host for Carson. He was the last surviving member of the Rat Pack.
His sidekick Regis, well, whatever happened to the lad?