One of the big differences in comics these days is that, back in the latter part of the Silver Age, DC treated virtually all of their heroes with equal care and importance. Not so today, as someone like The Atom would be considered a second or third string hero.
As it is, Atom (Pat Harrington) was one of the rotating middle features during Aquaman's half of the Superman-Aquaman Hour of Adventure, and also appeared in the Justice League of America shorts. In the comics, he was often teaming with Hawkman, but was usually partnered with Flash in the JLA stories on TV. Anyway, here's the Mighty Mite in a solo short, "The House of Doom", written by DC vet George Kashdan. Narrator Ted Knight also voices Prof. Simms and the evil Dr. Lokar and his alien master.