 As settlers expanded their holdings into the Great Plains , they ran into land conflicts with Native American tribes . This resulted in frequent raids , massacres and armed conflicts , leading to the federal government creating multiple treaties with the Plains tribes , which generally involved establishing borders and reserving lands for the indigenous . As with many other treaties between the U.S. and Native Americans , they were soon broken , leading to huge wars . Over 1 @,@ 000 battles , big and small , were fought between the U.S. military and Native Americans before the tribes were forced out of their land onto reservations . 
