Mr and Mrs Superman, a feature in Superman Family (1974-1982), featured stories of the adventures of married Superman and Lois Lane of Earth-Two.
Even though Earth-Three was destroyed in the Anti-Monitor's anti-matter wave attacks, a new Crime Syndicate (called the "Crime Syndicate of Amerika") developed in the antimatter universe of Qward, which was very different in background and power base from the pre-Crisis Earth-Three group, though same in the number of members.
After the Kingdom event, Hypertime and divergent realities were revealed, but never supposed to be accessed, as stated in the Zero Hour event.
He claims Gardner Fox's dreams were tuned into Earth-Two, explaining their depiction as a fictional world in earlier Barry Allen stories.
Superman was introduced in the 1930s and was the archetype for the modern superhero, and so is depicted in stories set on Earth-Two as the first major reliable costumed superhero on that world, discounting earlier part-time heroes and "mystery men" such as Dr. Most of the following costumed mystery men history is based on the Earth-Two Superman's initial appearance, where these previously independent operating heroes begin to reliably interact.
This was soon changed with alliances being formed between certain protagonists.
Several publications, including All Star Comics (publishing tales of the Justice Society of America), Leading Comics (publishing tales of the Seven Soldiers of Victory) and other comic books introduced a "shared universe" among several characters during the 1940s.
In order to distinguish him from the later primary version of the character, this Superman was called "Kal-L", using the spelling of Superman's Kryptonian name in his early appearances.
He was specifically introduced as an Earth-Two character in Justice League of America #73 (1969).
While it still houses a team of superheroes, its membership is younger than before.
Earth 2 also has a tragic backstory, having been invaded by a horde of alien invaders from Apokolips five years prior to the reboot, ahead of Darkseid's attempted invasion of Prime Earth.
In the 1970s, as the now annual team up between the Justice League of America and the Justice Society of America had proven popular, DC published the then present day adventures of the Justice Society in the revived All-Star Comics with issue 58, resuming the numbering from the series original run.