I’ve never understood why the societies in Mexico and South America evolved so much further than did those in North America.

Aboriginal people in Canada interacted with Europeans as far back as 1000 AD but prolonged contact came only after Europeans established permanent settlements in the 17th and 18th centuries. …

The Aboriginal population is estimated to have been between 200,000 and two million in the late 15th century. Repeated outbreaks of European infectious diseases such as influenza, measles and smallpox (to which they had no natural immunity), combined with other effects of European contact, resulted in a forty to eighty percent aboriginal population decrease post-contact. …