Captain America was the alter ego of Steve Rogers, a sickly young man who was enhanced to the peak of human perfection by an experimental serum in order to assist the United States conflict effort.
An deliberately patriotic creation, Captain America was often depicted combating the Axis powers of World Battle II in a costume that bears an American flag motif. He’s armed with an indestructible shield that can be thrown as a weapon.
After the war ended Captain America vanished, and was finally found and revived from suspended animation by the superhero crew the Avengers. Since then, Captain America has usually led the crew or been a part of it.