Quote from oldtime:
correct me if I am wrong, but I heard 90% of the indigenous population of North America died in the first hundred years since the first Europeans arrived. Mostly due to disease that they were not immune from.
Not that that really has anything to do with this discussion, but it's just something to think about.
As many before me have pointed out, we're not really sure if USA's success has anything to do with capitalism or just good luck and bad policies of exploiting resources we don't know how to replenish.