The Iroquois Council Meeting, which lead to the League of Nations and ultimately to the Iroquois Confederation Constitution, was similar to which gathering of
colonial leaders and why?

It is similar to the Continental Congress which forged unity among the colonies.

Explanation:

The Iroquois people were brave warriors who had once clashed for and against their neighbors. They contested over land and battled over blood feuds. When one individual was wronged in a group, the whole group reacted strongly and stormed violence against the offending tribe. federalist ideas were presented to the colonist by the Iroquois people that compelled the diverse tribes into unity in the same way diverse colonists forged unity against the colonial masters.