In the annals of children’s broadcasting, nothing can touch the reign of Sesame Street, currently in its 53rd season. Then there’s Mister Rogers’ Neighborhood, which ran 31 seasons on PBS. But not far behind is Captain Kangaroo, the CBS kids show that debuted in 1955 and continued for 29 years. It starred Bob Keeshan, who’d previously played Clarabell the Clown on NBC’s The Howdy Doody Show (14 seasons).

Dressed in a colorful overcoat with deep pockets (which is why they called him “Kangaroo”), Keeshan served as affable ringmaster over a loose format involving songs, puppets, cartoons and surprise guests who dropped by The Captain’s Place. In 1978, producer Jim Hirschfeld caught wind of John Burstein, an actor who’d created a “superhero of health” character named Slim Goodbody, complete with an educational stage show.

“Hirschfeld sent his production team to watch my show in New Jersey, and they really, really liked it,” recalls Burstein, 73. “And they say to me, ‘You are going to be on Captain Kangaroo.’ ”

It took Keeshan some convincing — Slim wore a bodysuit covered in human organs — but when Kraft Foods agreed to sponsor the segments, he relented, and Burstein appeared on the show until 1981. (Another recurring segment was “Picture Pages,” which was hosted by Bill Cosby from 1980 until the show’s cancellation in 1984.)

“Captain Kangaroo gave me the credibility that enabled my whole career to flow,” Burstein says. “I just got a royalty check today from Discovery streaming for stuff I did 35 years ago.”

This story first appeared in the June 7 issue of The Hollywood Reporter magazine. Click here to subscribe.