Captain America is a fictional superhero appearing in American comic books published by Marvel Comics. Created by cartoonists Joe Simon and Jack Kirby, the character first appeared in Captain America Comics #1 (cover dated March 1941) from Timely Comics, a predecessor of Marvel Comics.
Captain America was the first Marvel Comics character to have appeared in media outside comics with the release of the 1944 movie serial, Captain America. Since then, the character has been featured in other films and television series.
Source: Wikipedia, "Captain America", available under the CC-BY-SA License.