Why did so many Indians die as result of colonization and contact?

1 Answer

The biggest reason were diseases brought from Europe that the Indians had no resistance to .

Explanation:

Small pox was a massive killer to the people of the Americas.
Europeans had built up a resistance to small pox due to their exposure to animals. Cow pox a form of small pox worked to immunize many Europeans from small pox. The people of the Americas had few domesticated animals and had no opportunity to develop resistance. (See: "Guns Germs and Steel" by Jared Diamond)

Small pox decimated the Aztecs allowing the Spanish to conquer Mexico. In a early form of weapons of mass destruction, white settlers would trade blankets to the plains Indians that were infected with small pox. The resulting epidemic weakened the tribes allowing the settlers to encroach on Indian lands.