America has always been a big part of comics, hell two of the biggest comic book companies are based in America. Of course I’m talking about Marvel and Have you ever wondered how much influence it has on comics itself? Or the perception of America in the history of comics? 
Depending on the story or character. America can either be seen in a supporting role or as an antagonist. For example: Captain America. He has America in the name and his first appearance is punching Hitler square in the jaw.
He’s all about truth, justice and is the symbol of what makes America great. One might even say he was originally used for Propaganda during World War II. This was a time period were people were afraid of what could happen in America. So propaganda comics that could make the enemy (in this case Germany,Japan etc.) that it was necessary to have America be shown as heroes saving the innocents from the horrors of war. Might have even motivated some to become soldiers because of it. Comic books would even be shipped off to soldiers stationed on the battlefield as to give then something to do that wasn’t fearing for their lives. Of course having them and America be looked on as heroes during this struggling time.
Specific superheroes would also have visual cues to not have them be as a specific character but more as a representations of certain topics. A good example is Wonder Woman during this time. With most of the men fighting off in the war. Women would be the ones working with tech and weapons in an effort to help out in any way they can. Wonder Woman has always been a strong symbol for Feminism, so this was a perfect way to get comic book readers to relate to what they were doing. 
Of course America isn’t always seen as the good guy in comics. Sometimes even in American Comic’s themselves they’re seen more as puppet masters that have our heroes under their control. 
The Dark Knight Returns by Frank Miller does that exact thing to Superman. The president has him under his control where he can only use his powers when the Government decides he can. They’ll send him out on jobs, have him literally fight one man wars, and even take down his fellow heroes if they get in the way. Needless to say America while not looking like the total bad guy, they do have a negative light shine on them as they have this unstoppable force that could destroy anything if they wanted to. 

Another more recent example is Civil War. Which the new Captain America movie with the same name is based on. In it the Government wants to take control of superheroes and similarly to TDKR have it where they can only use their powers when they get the OK too. In this story it’s Iron Man on the side of the Government with Captain America on the side of the people with numerous superheroes going on opposite sides of eachother. This one it’s actually a bit difficult to see if the American Government is in a bad light or not since it really depends on the perspective of the reader them self. 
American’s propaganda knows no bounds though as the U.S. Navy has even gone as far as to write a Manga entirely Japanese that sole purpose was to create and influence the Japanese masses about the home porting of the USS Washington that is literally a nuclear powered supercarrier, it was due to the controversy about the carrier that the manga was created.
Titled CVN-73 the manga stars Jack O’Hara, an American man of Japanese decent on comic adventures throughout the ship and local sights of Japan itself in an attempt to make the U.S. Navy seem both more relatable and more human to the Japanese population.

The manga turned out to be popular with younger readers and considered harmless if not a bit boring for the older crown. 

America seems to always have s big part to play in media and comic books is definitely no exception. Sometimes seen as the big hero or the big bad. It’s always seen as a powerful entity, which is how it’s seen in real life also.

Makes one wonder with how the country itself will evolve and who out future leader will become later this year, if that will affect any storylines or characters in the comics themselves. One can only wait and see.