The Columbian Exchange made the Conquest of America easier in several ways. On the one hand, the exchange meant that natives and Europeans interacted more, leading to more disease and abuses which decimated the natives. On the other hand, the exchange also gave the natives a reason to cooperate with Europeans, as they wanted to participate in the trade. This made them less defensive. Finally, many native rulers were interested in benefitting from the new goods that the Europeans brought, which made them less careful about the Europeans.
The Columbus exchange brought sickness for the natives which eliminated most of their population. This eliminated the chance of any form of a stand from them.
