Although Ted Knight, the original Starman, was his father, Jack cared little for the world of super-heroes, preferring his career as a collectibles dealer. However, when his brother, David, was killed in action shortly after taking on the role of Starman, Jack was forced into taking up the cosmic rod in order to protect Opal City and bring his brother's killer to justice. Since then, he imperceptibly came to love his role as Opal's protector, and found that he enjoyed being a hero. Recently, he embarked on a year-long quest in space to find Will Payton, his girlfriend Sadie's brother and a former Starman. He was eventually successful in his quest, but did not bring Payton back to Earth since the latter discovered he may be the reincarnation of an alien prince.
Jack agreed to be a member of the Justice Society after the mission to ensure Fate's reincarnation, but following events in Opal City which kept him away for some time, he reconsidered and become a reservist, called in when the group was in desperate need of additional firepower. Later still, following the death of his father, and Sadie's announcement that she was pregnant, he decided to step down from the heroic world altogether in order to rear his two children (the first having been sired without his knowledge when he was raped by the Mist), passing the cosmic rod onto Courtney Whitmore, the current Star-Spangled Kid.