I remember him. He was supposedly a more intellectual version of Carson. Basically his show ran in the early 1970s. This is the rundown of his time on tv. As you can see he was at his peak at the beginning and steadily declined. Carson was the king, Merv Griffin was next in line and Cavett brought up the rear so to speak. In those days generally I mostly went with Carson unless the others had a guest I was interested in.
Intermittently since 1968, Cavett has been host of his own talk show, in various formats and on various television and radio networks:
ABC (1968–1974)
CBS (1975)
PBS (1977–1982)
USA Network (1985–1986)
Olympia Broadcasting (syndicated radio show, 1985–1989)
ABC (1986–1987)
CNBC (1989–1996)
Turner Classic Movies (2006–2007)
he has a good interview with Katherine Hepburn and one with Groucho on YouTube.