Good ol' America

I always thought that Wonder Woman was the "female version" of Superman, but it turns out that she was created with Captain America in mind who was created by Timely Comics (Marvel Comics). Captain America was a huge success after being released in March 1941, which was right in the middle of World War II era. In response, an immortal Amazonian princess warrior from fictional Greek mythology was made as American as humanly possible.

Looking at the the picture above, we can see the red, white, and blue of the flag. We can see the stars as well as the golden eagle, one of the many icons of the United States of America. 

Hypothetically, I think that Diana or Wonder Woman would still be the same person even if she went to a different country or community because of the values she was raised with on Paradise Island. The origins of how she became a superhero are heavily based on the fact that she fell in love with an American soldier, Steve Trevor, who washed up onto the island. Then, the Greek goddesses, Aphrodite and Athena, insisted that the Amazons help fight against hate and oppression during the time of the war. Okay, that sounds valid, but they (the authors/artists) really push that "American liberty and freedom must be preserved" because it is the "last citadel of democracy and of equal rights for women." With these instructions, Hippolyte designs an overt American costume for the Amazon who would take Steve Trevor home. The only reason Diana wanted to leave the island was to take care of Steve who may be a shout out to Captain America because his name is also Steve and he is also an American soldier with blond hair. 

Captain America

Steve Trevor

Later on, when American patriotism was no longer the focus, Diana's costume toned down or changed completely. The eagle would either become more subtle or transform into a W. She wore shorts, a jumpsuit, pants, jackets, and on and on. I think that a subtle eagle is still drawn in and the colors are kept out of respect for the history of Wonder Woman.  Yes, it would be cool to see Wonder Woman in alternate universes where she decides to leave the island for different reasons and has a different costume, but we can't ignore the history and have to appreciate the influence that Wonder Woman has spread as the first female superhero.