The reason for the Iroquois tribes to form the Great League of Peace was to maintain good relations between their communities. They wanted to stick together and support each other so that they can face any problems as a union and thus be stronger, and to preserve their culture, language, traditions. Unfortunately, it didn't turned out as they planned, and during the American Revolution they were forced to choose a side between the British and the Americans in order to preserve their independence.
The outer garment worn in rainy weather is known as the inverness.
Yes that was the purpose if the bill of rights