US has become the most powerful country because of the countries it has colonized. The influence they made to countries they manipulated. But when you look at the statistics today, it's different not.
I would disagree. The Americans have not engaged in colonialism as much as the Brits or the Spaniards. They became powerful because they didn't participated in the world wars (they participated in the WW2, but only when the Axis powers were losing). As a result, the other super-powers of that time became weak, and the Americans became stronger.