The United States has impacted the world in a number of ways. Spreading capitalism in principle and deed might be America's greatest legacy, but the US has also attempted to protect the interests of capitalist democracy around the world with arms.
A superpower has the abiltiy to militarily, politically, and econcomically influence all areas of the world, not just those in its immediate geographical area. The United States has exerted this kind of influence in the world since World War II. Our influence is seen in the emergence of other countries that align with us politically and help us further our global agenda.