Rex Richards was a member of the Allied Supermen of America. Like many of the members, he was based off of a Justice League of America member. In his case, he was based on the Flash. He possesses super speed.
Halfway through 1950, the Allied Supermen of America disbanded and Roc Rocket marries teammate Alley Cat. Together, they have children and grandchildren. His granddaughter Rachel Richards took on the mantle of Doc Rocket as a member of Youngblood.
Supreme: Blue Rose
Doc Rocket appears in Supreme: Blue Rose, but his ethnicity has changed from being Caucasian to African-American. He teams up with Diana Dane to locate Ethan Crane.