We all know one of the biggest reasons the Europeans were able to rapidly conquer the Americas was because more than 90% of the people were eradicated with European diseases that the natives weren't exposed to, therefore weren't immune to. Is there any evidence of major outbreaks caused by Leif Erikson's expedition, and if so, why didn't it spread throughout the continent?
While there's always more that can be said, you might like to have a read through some of these previous questions on the subject.
If the Vikings visited North America before 1492, was there any evidence that any population was wiped out (partially or otherwise) by small pox? by /u/Reedstilt.
And One of the main reasons Europeans were so utterly victorious against Native Americans was the introduction of diseases, that decimated the population. Why did the Norsemen of Vinland not bring diseases that carried the same effect? primarily by /u/anthropology_nerd.