Adam was the son of Superman and Lois Lane born shortly after a plague began to kill all men on the planet. Convinced he was the carrier of the virus, Superman left Earth, but not before leaving DNA samples behind so that the Earth could still be populated. Later Adam and his new brothers and sisters were taken to be raised by the Amazons when it became evident that the human mothers couldn't handle babies with half the powers of Superman. As a teenager, Adam was convinced by Lex Luthor to revolt against being raised by women as men were superior, and rallied his brothers to fight against the Amazons and the all-female JLA. But the fight was quelled when Superman returned, no longer a virus carrier and convinced Adam to stop the revolt.
Adam has all the powers of Superman but at half the normal Kryptonian capacity