== His chronology == 

 Shortly after wrapping up JJ's original solo series the article states, "His appearances with the [Justice] League kept him in the public eye long after his own series was cancelled....From the late 1960s until the late 1970s, J'onn was absent from the JLA, having left Earth to find and become leader of New Mars. This time period is later retconned during the Crisis on Infinite Earths, and his period of absence is never again referenced." Not so. Shortly after his HoM feature ended, he made his first appearance in JLA in some time, leaving Earth with the Martians who have finally come for him. After this, he made very sporadic appearances for over a decade. He teamed up with Superman while World's Finest Comics was temporarily Batman-less, appeared in one 1974 issue of JLA, had a three-issue back-up miniseries in Adventure Comics that led directly into a team-up with Supes and Bats in World's Finest, did another isolated guest shot in JLA (playing cosmic-level chess with Despero), and permanently resurfaced in JLA when the book was severely reformatted (the satellite HQ was destroyed, Aquaman became chairman, new members included the similarly enhanced son of Steel the Indestructible Man, and a break-dancer). I don't think I missed anything. Over the course of these appearances, things on New Mars were developed. I am also unaware of any retconning away, via Crisis or any other way, of this period. Indeed, the early issues of the John Ostrander-written Martian Manhunter series (all I read because understanding the plot required more knowledge of what was going on in the League's own series than I had or wanted to get) seemed to deal with J'onzz's off-Earth period heavily, contradicting this assertion. I'd say this article needs a lot of help.