Says who? Just because you think so doesn't make it true. FYI dumbass, America was populated by Natives long before any European stepped foot there. Try taking your head out of your ass long enough to get a fucking clue, or better yet, kill yourself for being an ignorant piece of shit.
Its pretty simple, America was founded as a white country, said white Europeans of good moral character, and American means a mix of white European blood. As someone from Iraq can never be "Swedish", someone from Mexico can never be American. They can be a resident in America, maybe they can game the system for "citizenship" but they will always be Mexican, or Guatemalan, or Salvadoran, but they wont be white.