For example, I remember the Hot Wheels and Skyhawks programs. They were shown back to back on ABC 1969 - 1971.
(I'm slightly surprised I got to see them since we only had two channels and they didn't show ABC shows unless they were popular; that's why I missed the first season of The Six Million Dollar Man.)
Hot Wheels was, obviously, named for the toy cars. I don't know if there were "Skyhawk" toys. Maybe.
But here were two things I loved: cars and airplanes. Now, some 53 years later, I only have vague images from the two shows. I do remember catching Skyhawks re-using footage (I was around 10 at the time). Which they probably did more than I caught.
I remembered that they were 15 minutes each so they totaled 30 minutes. But according to the interwebs, they were 30 minutes each.
I guess they were canceled because the FCC thought they were just half-hour long ads for toys.
Most people I've asked don't remember these cartoons. For a while I worried that I made them up (or at least made up Skyhawks).
Hot Wheels has it's own Wikipedia page. Skyhawks has an IMDB page. Which is the only tangible evidence I have that these two shows existed.
Did you have a cartoon you liked but almost no one remembers? Do you remember Hot Wheels and Skyhawks? Let me know in the comments below.