Barnes learns of Rogers' dual identity and offers to keep the secret if he can become Captain America's sidekick. During their adventures, Franklin D. Roosevelt presents Captain America with a new shield, forged from an alloy of steel and vibranium, fused by an unknown catalyst, so effective that it replaces his own firearm. Throughout World War II, Captain America and Bucky fight the Nazi menace both on their own and as members of the superhero team the Invaders as seen in the 1970s comic of the same name. Captain America fights in numerous battles in World War II, primarily as a member of 1st Battalion, 26th Infantry Regiment "Blue Spaders". Captain America battles a number of criminal menaces on American soil, including a wide variety of costumed villains: the Wax Man, the Hangman, the Fang, the Black Talon, and the White Death, among others.