Justice League of America [Superman (Earth-1); Batman (Earth-1); The Flash [Barry Allen]; Green Lantern [Hal Jordan]; Black Canary; Elongated Man]; Justice Society of America [Sandman [Wesley Dodds]; Dr. Fate]; The Freedom Fighters [Human Bomb; Phantom Lady [Sandra Knight]; Doll Man; Uncle Sam; The Ray; Black Condor]
Red Tornado [John Smith]; Justice League of America [Green Lantern [Hal Jordan]; Black Canary; Elongated Man; The Flash [Barry Allen]; Batman (Earth-1); Green Arrow (Earth-1)]; Justice Society of America [The Flash [Jay Garrick]; Dr. Fate; Hourman [Rex Tyler]; Sandman [Wesley Dodds]; Superman (Earth-2)]; The Freedom Fighters [Black Condor; The Ray; Uncle Sam; Phantom Lady [Sandra Knight]; Doll Man; Human Bomb] (intro as a group); Adolf Hitler (poster); Plastic Man (flashback); The Blackhawks (flashback)
The Flash [Barry Allen]; Green Arrow (Earth-1); Batman (Earth-1); Black Canary; Green Lantern [Hal Jordan]; The Atom [Ray Palmer]; Aquaman [Arthur Curry]
Matamorpho; Creeper; Batman (Earth-2); Robin (Earth-2); Superman (Earth-1); Black Canary; Aquaman; Wonder Woman (Earth-1); Elongated Man; Green Arrow (Earth-1); Green Lantern [Hal Jordan]; Red Tornado; The Flash [Barry Allen]
Doll Man [Darrel Dane]; Elmo (first appearance; a dog; appears in many Doll Man stories hereafter); Miss Tiller and her gang (first appearance; villains)