It would be a strange thing if six nations of ignorant savages should be capable of forming a scheme for such a union, and be able to executive it in such a manner as that it has subsisted for ages and appears indissoluble, and yet that a like union should be impracticable for ten or a dozen English colonies, to whom it is more necessary and must be more advantageous, and who cannot be supposed to want an equal understanding of their interests.
Of course - Ben Franklin was well aquainted with the political and military confederation my ancestors created BEFORE the Europeans arrived. He figured if a bunch of ignorant savages could build such a successful political system, why couldn't the "Americans"?
Many of the founders were familiar with the 5, later 6, Nations - they were the dominant political power on the North American Continent (the "empire" stretched from Northeastern Canada, down well south of Virginia, and east to the Mississippi/Missouri River) prior to and during the colonial period...