There are few Avengers that get under Captain America’s skin quite like Iron Man especially after the two had a massive falling out during the events of Civil War, though after taking a look at the origins of the Avengers as an established team, it becomes clear that Captain America’s greatest superhero rival isn’t Iron Man–it’s Hawkeye.
During the events of Civil War by Mark Millar and Steve McNiven, Marvel’s superheroes find themselves under a great deal of scrutiny as their ability to carry out their own brand of vigilante justice with impunity is met with the idea of governmental oversight to ensure everyone can be held accountable for their actions. While Iron Man is on board with the idea, Captain America can’t fathom having to answer to a higher power before being sent on an Avengers mission. This disagreement leads to violent conflict as heroes and villains alike choose sides between those who wouldn’t mind some oversight and those who are willing to fight to keep things exactly the same with Iron Man and Captain America leading their respective sides. Even after the fighting was done and everything basically returned to normal as it stands currently in Marvel Comics continuity, Iron Man and Captain America still never fully recovered from Civil War despite their decision to fight side by side once more afterwards. This caused many to regard their relationship as the one with the most friction out of all of the Avengers, though the Avengers’ earliest storylines reveal that isn’t actually the case.
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In Avengers #21 by Stan Lee and Don Heck, the Avengers are keeping themselves busy within their headquarters as they weren’t facing any
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