As for a “usurped continent”, the land was very sparsely populated by the natives compared to the people who came in, and disease cleared out more of them making a vast underpopulation. It’s just not right to say that so few people should get to control the entire continent just because they were there first. Also I would guess you are a liberal from your comments, and therefore likely support legalizing undocumented immigrants. According to your logic, undocumented immigrants are “usurping” America, which is quite unpopular among liberals today.
America committed plenty of evils, but that’s not what made America great. In addition to many bad things, the USA did a lot of things right. I believe the USA had a lot of benefits from geography, but the real thing that made the country great was recognizing the rights of the individual. It has been demonstrated over and over again that egalitarianism yields big dividends in groups. Because the USA had such an emphasis on equality (declaration of independence), innovation occurred on an incredible level. It took a long time for that equality to spread to blacks, but the very idea of even equality of whites was unheard of at the time of the USA founding.
Combine that with the fact that Europe was devastated by two world wars, it was inevitable that the USA should pull ahead.