In which way did the Iroquois Confederacy resemble the constitutional government of the United States?

The Iroquois Confederation is the oldest association of its kind in North America. Although some scholars believe that the Five Nations (Oneida, Onondaga, Cayuga, Mohawk, and Seneca) formed their Iroquois League in the 12th century, the most popular theory holds that the confederation was created around 1450, before Columbus’ "discovery" of America. These five nations bore common linguistic and cultural characteristics, and they formed the alliance to protect themselves from invasion and to deliberate on common causes. In the 18th century, the Tuscarora joined the league to increase the membership to six nations.