My knowledge on the matter is limited to watching a few documentaries. On one hand, it states that the various Native American societies had no contact with each other, and most of the time didn't know of the others existence. On the other hand, European-brought diseases such as smallpox spread like wildfire to the Native American societies. Did this involve each tribe individually meeting Europeans, or is one of my assumptions wrong or am I missing something?
Edit: For the sake of my question, I should have put an emphasis on Central and South America
On one hand, it states that the various Native American societies had no contact with each other
This assumption is wrong. Just to give you an idea of the interconnectedness of North America, here's a map of western trade routes at the time of contact. It's based on a map in the Handbook of the North American Indians. While I don't have a similar map for the entire eastern part of the US, this map does show the major trails through the American Southeast during the early colonial period. Many of those trails extend all the way to the Great Lakes and the St. Lawrence River, and occasionally beyond, just as those western trade routes extend down into Mexico and north to Alaska.
These trails and trade routes carried European goods ahead of the Europeans themselves. Sadly, they also carried European diseases.
the various Native American societies had no contact with each other, and most of the time didn't know of the others existence.
I think you misinterpret this. Societies did not have direct contact, that is true, but a very indirect contact via a chain of neighboring societies was enough to spread the diseases.
