One purpose of the iroquois confederacy was to

Iroquios Confederacy was a group comprised of six (6) native related American tribes. These tribes were Seneca, Cayuga, Oneida, Mohawk, Onondaga, and Tuscarora. One of the major purposes of the banding together is in order to form an entity in politics. 

This confederation was the biggest of the political entity and they faced the European settlement in America. They fought wars including the Beaver Wars in which they fought against native Americans in Atlantic in order to control the trade of furs. 

I'm pretty sure that's called a volcano