Two vast continents were discovered by the Europeans in the Age of Discovery, and in both North and South America material technologies never developed the sophistication that we see in the other continents of the time. I'm in no way implying any group's superiority to the other, but what are some reasons the New World developed they way it did?
We get this question all the time. Here's a link to a response I made in the most recent one. It includes a link to the relevant section of the our FAQs.