The cause for Dawes act was to make it easier for Native Americans to become a part of the US society. Each Native American who wanted could get his US citizenship and a piece of land for himself that he wouldn't have to share with other Native Americans. The effect was that since many people now owned land individually, those people could make deals with the government and help the government expand by building infrastructure, which wasn't possible before since it was an open land that in its entirety belonged to the Natives.
