Old World diseases in the New World

Super Isolated environments, limited contact, and if many died from diseases, little record for us to prove it?

>>3016826
If smallpox had been brought to Vínland, Karlsefni's expedition would've been an unprecedented success and Norse colonies would spread throughout Canada, meaning that in 500 years most native civilizations would be ruined by low population and Norse raids.

>>3016976
Precolumbian america was pretty interconnected.

>>3017002
Not in Canada.

>>3016976
Oral histories aren't always the most reliable things, but they can be pretty accurate sometimes, especially with bigger events. Something like a devastating plague that might kill off a massive number of people and force the survivors to adapt or relocate or something might survive in the form of legends. I recall hearing, for instance, that the oral histories of some native Australian tribes contain information on major sea level rises from 10,000 years back which forced the alteration of hunting ground availability.

Another thing to consider is that, if the Vinlanders became more established (and thus enabled smallpox to spread), their interactions with the natives might have introduced the concept of written language to them as well, resulting in a Sequoya-like invention of "talking leaves" several hundred years ahead of schedule. Of course, the more established the Vinlanders become in this hypothetical timeline, the more likely it is other Old World ideas (such as the wheel) could cross-contaminate and spread into the continent, which could have all sorts of crazy consequences that go well beyond the scope of OP's question.