I think from a Joe Rohan podcast he said something along the lines of they had an Iroquois native sit upstairs as they wrote out the constitution to provide guidance as to what the Iroquois. Also side question that is unrelated, what would be some good choice of books to study Native American history?
If you don't get a full response here, you might find this thread, which links and contextualizes some previous answers, useful. (Hat tip to u/Reedstilt.)