"It would be a very strange thing if Six Nations of Ignorant Savages should be capable of forming a Scheme for such an Union and be able to execute it in such a manner, as that it has subsisted Ages, and appears indissoluble, and yet a like union should be impracticable for ten or a dozen English colonies." - Ben Franklin
"The only condition on earth to be compared with ours is that of the Indians, where they still have less law than we." - Thomas Jefferson, speaking of the Iroquois COnfederacy during the Constitutional Convention
"The fact is, that the condition of millions, in every country in Europe, is far worse than if they had been born before civilization began, or had been born among the Indians of North-America at the present day." - Thomas Paine, who was well aware of the Iroquois Confederacy, and wrote at length about them...
William Livingston, of New Jersey, spent at least a year, maybe more, living among the Mohawk (Iroquois) as a teenager - so, I'm pretty certain he would have been familiar with their system...
It is undisputed that Iroquoian leaders were present during, and participated in, debates when teh Declaration of Independence was in process...
I';ll have more examples later...