Who was Bucky Barnes in the original Captain America comics?

In the original Golden Age comics, Bucky Barnes was introduced as the plucky regimental mascot and kid sidekick to Steve Rogers, who had been transformed into the superhero Captain America. Together, the pair fought against the Axis powers on multiple fronts during World War II.1

During the final days of the war, Bucky was presumed dead after he and Captain America attempted to defuse a bomb on a drone aircraft that exploded over the North Atlantic. While later modern-era stories revealed that Bucky had actually survived the explosion and was transformed into the assassin known as the Winter Soldier, his original role in the 1940s comics was defined strictly as the young, enthusiastic partner assisting Captain America in his efforts against the Nazi threat.12