During World War II, two cosmic twins had different private lives although parallel public ones, due in large part to their age.
While Sylvester Pemberton on Earth-Two had been a wealthy teenage with a genius-level aptitude, Jack Weston was a young man in his early twenties who was no longer in school. As a result, he was an army private for whom his superior, General Milton, saw tremendous potential. So had Sylvester, in himself, and so both lads adopted similar blue, white and red costumes to fight the forces of evil terrorizing humanity. As the Star-Spangled Kid, Sylvester eventually met fellow hero Stripesy, and developed a long lasting partnership while employed Dugan as his chaffeur and mechanic. For Weston, he was a one-man army sent on various missions by his officer and mentor, and as the Minute-Man he soon developed a legendary career in his own right. While never meeting his world's Dugan, a Pat Gleason who assisted the costumed crusader known as Devil's Dagger, Minute-Man did find allies among his fellow mystery men. As a member of the Crime Crusaders Club alongside Captain Marvel Jr., Bulletman and Bulletgirl, he found long lasting friends. So did the Kid, as a member of Law's Legionnaires.
Due to the machinations of villains, both heroes were catapulted from their era and reappeared in the mid-70's. Syl resumed his heroic career, although Jack only resumed his alias on occasion and mostly retired as a restauranteur. While Jack has little in similarity with his Earth-One twin, Star Boy, both seem to manifest the ability to tackle weighty matters with equal parts valor and victory.