Without the desire to sound or intent to be snotty, I did explicitly refer to the civilizations of the americas existing in isolation from those on the western seaboard of the Atlantic and Eastern seaboard of the Pacific.
I am not sure what you mean by isolated.
Whether this was the case has been widey debated by those more knowledgeable than I will ever be, but fascinating to speculate. I feel the need, in the light of the politicisation of this otherwise intriguing topic, to add that I have no strong opinions either way, re the deep/ancient history of the Americas, and whether those civilizations were isolated from Europe, Africa and/or Asia or not
I think that Native Americans were more interconnected than you realize. When I first read your comment, I read it as an isolation of cultures in the east and the west as we define them today... I must have been in a hurry, I apologize.
Since Native Americans, as we traditionally understand them, were living in relatively small communities (Cahokia is one example of where this is not true), there was not trade on the same scale that you see in other places but they were certainly not isolated... There were raw materials and resources being traded between groups throughout the continent... There were Algonquian speaking tribes from the East Coast of the united states, into western Canada, and the Great Plains... Those tribes were certainly trading and interacting with other tribes who are speaking the same language.
Were the Iroquoian speaking people of New York and Pennsylvania interacting directly with the Salish of the northwestern United States??? Probably not, but trade was occurring between groups on the opposite seaboards... Perhaps the groups were not trading directly but material and technology was certainly being shared through intermediary groups located in between...
It all depends on how you want to define "isolation"... There were certainly groups that never directly interacted but I think it is safe to say that they were indirectly influencing each other. With the huge range of the Algonquin speaking peoples, they were certainly influencing groups over a wide breadth... I refer back to the Algonquin because they are the most obvious example.
Here is a map illustrating trade from the center of the United States Westward. It doesn't show the detailed path of trade eastward but it does illustrate that ideas and goods were also heading in that direction:
Here is a 2nd map that shows the range of different Native American language groups. The Algonquin range is most telling. This map doesn't show Canada but there were Algonquin speaking groups located in more western canadian locations than in the States:
The idea that these groups were not influencing each other is outdated. They all had their own customs, traditional food sources, and traditional tool making technology but advances in technology and goods were being passed from one coast to the next, though be it slowly....
*These statements are regarding later era Native Americans of Northern America... There were huge native american cities/civilizations that rose and fell in Central and South America who were also influencing a wide area with trade.
Edited by PJammer24, 08 January 2019 - 04:07 PM.