After their sitcom had bombed during the 1965-6 season, the Smothers Brothers returned a year later with the now legendary Smothers Brothers Comedy Hour, which was posited in CBS' Sunday lineup, opposite Bonanza on NBC and The ABC Sunday Night Movie.
Tom & Dick Smothers went in a different direction than the average variety show. They courted controversy by attracting guests with political messages, presenting satirical sketches that had CBS' censors reaching for the pruning shears, if you will. The series' initial success can be attributed in no small part to having The Ed Sullivan Show as a lead-in. I believe the initial run of What's My Line? was coming to an end, and if memory serves from past research, Line was coupled with Candid Camera in back of the Smothers Brothers.
As they say, you can't fight city hall, and inevitably, the series was cancelled in the spring of 1969 after 2 full years, 3 seasons, on the air.
I had misspoken when I said that the brothers' 1980's NBC series, Fitz & Bones, was their last series. It wasn't. They revived The Smothers Brothers Comedy Hour in 1988 in the wake of a writers' strike, but it was just a short-term deal. Same went for a 1975 revival, also for NBC. In 1993, E! picked up the 1967-9 series, and brought in Tom & Dick Smothers to do wraparound segments to acquaint a new generation of viewers with their original variety show.
Following is a September 1968 episode, taken from the E! run, with the intro by Tom & Dick Smothers. Musical guests are Mama Cass Elliott and Harry Belafonte.
I didn't see enough of the E! rerun cycle to form an opinion, so there won't be a rating.