The foes of the Justice Society of America....Fiddler, Icicle and the Wizard, the villains from Earth-2 (where the Justice Society of America lived) where the ones who initiated the team-up, crossing over from their Earth (Earth-2) to Earth-1 (and they captured the two Flashes, who had a few team-ups before....).
FiddlerJay and Barry Allen) in the Flash #123 (September, 1961), just before joining the Crime Champions. After the first battle with the JLA and JSA, Fiddler returned first for a solo battle with Jay Garrick in Flash #201 (November, 1970), then was a part of the Injustice Society of the World (and its update, Injustice, Unlimited, to face Infinity, Inc.) for most of his returns after (though he did stop by to face the Teen Titans once), at least until meeting his final fate with the Secret Six.
IcicleSportsmaster and the Huntress as well), before throwing his cold gun in to help out the Crime Champions. The Icicle was a loyal member of the ISW, making all his appearances after the meeting with the Crime Champions as a member of the ISW (starting with Justice League of America #123 of October, 1975, except when he worked with the Crime Champions again, or faced his end during the Crisis On Infinite Earths). But, the Icicle legacy lived on with his son taking over the name (and he had ice powers of his own!).
WizardVandal Savage and Per Degaton, among others), and #41, before joining the Crime Champions (though later historical inserts add the Wizard as the man who helped the Golden Age Superman marry Lois Lane, and who cursed the young Dinah Laurel Lance, giving her what became the "Canary Cry" when she became the second Black Canary). After using his magical powers to work with the Crime Champions, Wizard also returned as a member of the Injustice Society of the World to face the JLA and JSA in Justice League of America #123 of October, 1975), but the Wizard had bigger aspirations, also working with the Secret Society of Super-Villains and later, Injustice, Unlimited, to continue to menace all generations of heroes.
Chronos also led groups of villains over time), and only returned one more time, in Justice League of America #219 and #220 (October and November, 1983) where they worked with the evil Earth-1 version of Johnny Thunder (and learned of the history of the two Black Canaries), though it was with the second version of Dr. Alchemy. Still, the Crime Champions were a building block of villainy, allowing for larger groups of villains to form in the future.