The battle of little bighorn was but one battle in the sioux war of 1876-1877. what was the cause of this war?
a)gold was discovered at sutter's mill in california.
b)congress passed the removal act.
c)the ghost dance religion encouraged indians to go on the warpath.
d)miners entered the black hills, in what is now western south dakota.

The correct answer is D)Miners entered the Black Hills, in what is now western South Dakota.

Simply put, gold was discovered in the Black hills and miners entered without caring for the Native Americans who lived there. The Natives decided not to allow the United States officials to take the land away from them by force so they fought a war. The United States won in the end.