I remember Captain Fortune very well, given that I am now 70.
For some reason, I remember it as a daily show, not a Saturday show.
Somehow, he was featured "jumping" off a slowly moving cable car ... at the beginning of his show ?
And he was a talented cartoonist. Kid-guests would draw a squiggle, and he'd turn it into a recognizable cartoon.
And then ... one day ... at the end of his show ... he announced that "from now on, it won't be Captain Fortune, it will be Captain Kangaroo."
And apparently the SF Chronicle the next morning announced in an article that he was the subject of a paternity suit. Back then, that sort of "scandal" spelled the end for a "respectable" career.
Sad, since Captain Kangaroo was such a loser and a jerk, and was NO replacement for Captain Fortune.