the widespread transfer of plants, animals, culture, human populations, technology, and ideas between the Americas and the Old World in the 15th and 16th centuries, related to European colonization and trade after Christopher Columbus's 1492 voyage
The people of the Americas had never been exposed to such infectious diseases as measles and smallpox. Without any resistance to those diseases, they were helpless and died in huge numbers. This is the most important impact of the exchange because of the fact that it was so devastating to the native population.
