It would be the "legislative branch" that is divided into two separate chambers--one is called the Senate and the other is called the House of Representatives. This is called a "bicameral" legislature.
Damage infrastructure lack of raw materials reduced trade due to destruction of shipping fleets loss of national and total political leaders
Generally speaking, westward migration had a very negative impact on the Indian's way of life, since a large majority of Natives were either displaced from their homes or killed in order to make way for white settlements.
Climate should be a good factor