Captain America is a fictional comic book superhero published by Marvel Comics. Created by Joe Simon and Jack Kirby, he first appeared in Captain America Comics #1 (March 1941), from Marvel Comics' 1940s predecessor, Timely Comics.[1] Over the years, an estimated 210 million copies of "Captain America" comic books have been sold in a total of 75 countries.[2] While the term "Captain America" technically applies to whomever is chosen to wear the costume and given the Shield (the U.S. Government sees itself as "owning" the persona), for nearly all of the character's publication history Captain America was the alter ego of Steve Rogers,[3] a sickly young man who was given enhanced strength and reflexes by an experimental serum in order to aid the United States war effort. Captain America wears a costume that utilizes an American flag motif, and is armed with an indestructible shield that can be thrown as a weapon.