Many Americans have committed no evil at all and are just regular people trying to enjoy their lives the best they can with their given circumstances.
That's the reason why we should never generalise: we tend to use labels in order to make easier our reasonings, but it leads to our fall into fallacies and other biases. Nothing is black or white, and not all Americans (or Europeans, Africans...) are the same.
You only have to take off the bandage of hate and open your eyes. Why so many people still fall into this trap?