They were first discovered A. D. 1608. About 1675, they attained their culminating point when their dominion reached over an area remarkably large, covering the greater parts of New York, Pennsylvania and Ohio,[85] and portions of Canada north of Lake Ontario. At the time of their discovery they were the highest representatives of the Red Race north of New Mexico in intelligence and advancement, though perhaps inferior to some of the Gulf tribes in the arts of life. In the extent and quality of their mental endowments they must be ranked among the highest Indians in America. Although they have declined in numbers there are still four thousand Iroquois in New York, about a thousand in Canada, and near that number in the West; thus illustrating the efficiency as well as persistency of the arts of barbarous life in sustaining existence. It is now said that they are slowly increasing.
When the confederacy was formed, about A. D. 1400-1450,[86] the conditions previously named were present. The Iroquois was in five independent tribes, occupied territories contiguous to each other, and spoke dialects of the same language which were mutually intelligible. Beside these facts certain gentes were common in the several tribes as has been shown. In their relations to each other, as separated parts of the same gens, these common gentes afforded a natural and enduring basis for a confederacy. With these elements existing, the formation of a confederacy became a question of intelligence and skill. Other tribes in large numbers were standing in precisely the same relations in different parts of the continent without confederating. The fact that the Iroquois tribes accomplished the work affords evidence of their superior capacity. Moreover, as the confederacy was the ultimate stage of organization among the American aborigines its existence would be expected in the most intelligent tribes only.
It is affirmed by the Iroquois that the confederacy was formed by a council of wise-men and chiefs of the five tribes which met for that purpose on the north shore of Onondaga lake, near the site of Syracuse; and that before its session was concluded the organization was perfected, and set in immediate operation. At their periodical councils for raising up sachems they still explain its origin as the result of one protracted effort of legislation. It was probably a consequence of a previous alliance for mutual defense, the advantages of which they had perceived and which they sought to render permanent.