For example, would the Aztecs have known about the assorted Algonquin tribes, or would the Incas have known about the peoples of the Amazon? Not those cultures specifically, but a more general sense (with variation between different cultures).
Hi there, while there's always more to be said on this topic, you may be interested in the section of our FAQs about pre-Columbian trade and contact among native American groups.
Because many of the threads in that section are now archived, if you have a question for one of the posters, feel free to just mention their username here with your question. (In other words, say "hey /u/jschooltiger can you tell me more about ...) You can mention up to three usernames per comment, and those users will get a notification.
Hope this helps!