WW1 and two jump started the American economy to rise to a high that was never seen before until then. WW1 and WW2 left the European empires and great powers weaker and in debt, this made them rely on the American economy. After WW2, Europe was weaker and the great empires where forced to release their colonies across the world in order to survive through the Cold War. This allowed America to rapidly expand its influence across the world.
