The series was introduced, together with the rest of that years Saturday morning lineup, in a TV special titled the "ABC Super Saturday Club Special". Broadcast Tuesday, September 4th 1969, the special was presented by the cast of Madame et son fantôme (1968), in character, watching clips of the upcoming shows on their TV. Having enjoyed the footage of the animated Hardy Boys, the Captain (Edward Mulhare) appeared and used his magical powers to summon the live action Hardy Boys into the Muir living room to perform a musical number.
The first animated series to feature a regular African-American character.
Unlike the Archies, a group of musicians were recruited by Bill Traut and Jim Golden of Dunwich Productions, Chicago with the help of the film's producers, Filmation, to record for RCA and go out on the road to perform the songs live.
First Filmation series to feature public service announcements by the main characters at the end of each episode.
First Filmation production to feature the rotating credit for producers Lou Scheimer and Norm Prescott, which was introduced so each would receive equal billing and neither one of them would be credited on top.