Shazam! ran for three seasons (28 episodes) between 1974 and 1976. It should be noted that the wizard Shazam, who empowers Captain Marvel in the comic book and serves as his mentor, does not appear in the series. Teenage Billy instead speaks directly to the elders that empowered him (who appeared as animated characters): Solomon, Hercules, Atlas, Zeus, Achilles, and Mercury) via a communication device.
Instead of being based in any one particular city, Billy (Michael Gray) and his traveling companion Mentor (Les Tremayne) travelled through California in an RV, interacting with people in various towns they stop in.
Whenever a potentially dangerous situation arose, Billy would become Captain Marvel and save the day. In an era before cell phones, Mentor would make phone calls from the RV on a type of mobile phone, asking a “mobile operator” to dial the number.
While the series was on the air in 1976, DC’s Shazam! comic book was modified somewhat to reflect the format of the TV series, with Billy Batson traveling across the country aboard a van furnished by his employer, station W.H.I.Z., contacting the six elders via the “Eterni-Phone”, and with Uncle Dudley, an established character in the source material, taking on a role similar to the Les Tremayne Mentor character.
There were no such super-villains as Dr. Sivana, Captain Marvel’s greatest enemy in the comics, and violence was downplayed. Billy, as both himself and as Captain Marvel, would help people out of difficult situations of their own making. Occasionally Captain Marvel would team up with fellow hero Isis, crossing over with television show The Secrets of Isis.
As in many Filmation shows and cartoons, moral messages were contained within each episode, crystallized at the end of each episode by Billy learning a new moral lesson from either Mentor or his empowering elders.
As in other media, when he spoke the magic word “Shazam!” Billy would be struck by a magic lightning bolt and would be transformed via animation and special effects into Captain Marvel, the World’s Mightiest Mortal.