A political league for offense and defense was sometimes formed by two or more tribes, who entered into a compact or formal statement of principles to govern their separate and collective action. A looser, less formal, and less cohesive alliance of tribes was sometimes formed to meet some grave temporary emergency. The unit of a confederation is the organized tribe, just as the clan or gene is the unit of the tribe.
The confederation has a supreme council composed of representatives form the several contracting tribes of which it is composed. The tribes forming a confederation surrendered to the league certain powers and rights which they had exercised individually. The executive, legislative, and judicial functions of the confederation were exercised by the supreme council through instruments appointed in the compact or afterward devised. Every tribe of the confederation was generally entitled to representation in the supreme federal council. The chiefs of the federal council and the sub-chiefs of each tribe constituted the local council of the tribe. The confirmation of officials and their installation were functions delegated to the officers of the confederation. The supreme federal council had practically the same officers as a tribal council, namely, a speaker, fire-keeper, doorkeeper, and wampum-keeper or annalist.
In the Iroquoian confederation the original 5 tribes severally had a supreme war chief, the name and the title of whom were hereditary in certain specified clans. The supreme federal council, sitting as a court without a jury, heard and determined causes in accordance with established principles and rules. The representation in the council of the Iroquois confederation was not based on the clan as its unit, for many clans had no representative in the federal council, while others had several. The supreme federal council of this confederation was organized on the basis of tribal phratries or brotherhoods of tribes, of which one phratry acted as do the presiding judges of a court sitting without a jury, having power to confirm, or on constitutional or other grounds to reject, the votes or conclusions of the two other phratries acting individually, but having no right to discuss any question beyond suggesting means to the other phratries for reaching an agreement or compromise, in the event that they offer differing votes or opinions, and at all times being jealously careful of the customs, rules, principles, and precedents of the council, requiring procedure strictly to conform to these where possible. The constituent tribes of the Iroquois confederation, the Mohawk, Oneida, Onondaga, Cayuga, and Seneca, constituted three tribal phratries, of which the Mohawk and Seneca formed the first, the Oneida and Cayuga the second, and the Onondaga the third; but in ceremonial and festal assemblies the last tribe affiliated with the Mohawk-Seneca phratry.
Among the looser confederations, properly alliances, may be mentioned that of the Chippewa, Ottawa, and Potawatomi; the 7 council fires of the Dakota; and the alliance of the tribes of Virginia and Maryland called the Powhatan confederacy. To these may be added the loose Caddo confederacy, which, like the others, was held together largely by religious affiliation. The records are insufficient to define with accuracy the political organization of these groups.