History
As a member of the Greatest Generation, Steve Rogers spent his days in WWII taking down Nazis and battling the infamous Red Skull. This was the era when the legend known as the Sentinel of Liberty was born.
Cosmic Civil War[]
After the Collector used most of the ISO-Sphere's energy to defeat Maestro, Captain America decided to take the opportunity to escape Battlerealm once and for all.
To accomplish this mission, Captain America sought out the other champions of Battlerealm to help him, but not all of them agreed with him. Those who agreed with him joined him in the Blue Faction, while those who didn't joined Iron Man's Iron Faction, and what was a disagreement between Captain America and Iron Man quickly escalated into an open conflict between the two forces.
Cosmic Civil War: Endgame[]
As time passed, Captain America became obsessed with taking Iron Man down. That led many of his allies to leave his side in order to help Doctor Strange find the legendary Civil Warrior to convince him to end the war.
Captain America, along with Iron Man, were defeated by the Civil Warrior in the site of their final battle, thus ending the Cosmic Civil War. He was among the Champions who were recaptured by the Collector by the end of the war.