Captain America is a fictional character, a superhero that appears in comic books published by Marvel Comics. The character first appeared in Captain America Comics #1 (March 1941), from Marvel Comics' 1940s predecessor, Timely Comics,[1] and was created by Joe Simon and Jack Kirby. Over the years, an estimated 210 million copies of "Captain America" comic books have been sold in a total of 75 countries.[2] For nearly all of the character's publication history, 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 aid the United States war effort. Captain America wears a costume that bears an American flag motif, and is armed with an indestructible shield that can be thrown as a weapon.