Pre-Zero Hour History
Cosmic Boy and the other Legionaires summoned Supergirl from 1962 to the future in order to stop the rampage of the Positive Man. While she accomplished that task, he and the others were knocked out and replaced by Chameleon Men. Supergirl later rescued them. ("Supergirl's Greatest Challenge!")
Many years later, his son had taken over as Cosmic Boy. Along with the sons of Lightning Lad and Saturn Girl, this new Cosmic Boy traveled to the past to invite Supergirl to join the ranks of the Legion. However, she failed her entrance test. ("The Three Super-Heroes!")
- This was Supergirl's first meeting with the legion, from her perspective. However, after this meeting, subsequent stories dropped the angle of the characters being children of the originals.