The discovery of what resource, in 1874, in the Black Hills of South Dakota caused the U. S. government to break their treaty with the Dakota Sioux

Gold.

Explanation:

A series of clashes between the Northern Cheyenne, Lakota Sioux and the United States that took place in the years between 1876 and 1877 for the occupation of the Black Hills was known as the Great Sioux War. The discovery of the gold in the Black Hills and the U.S government's desire to establish its control over the Black Hills were the main causes of the war.

maybe #3? try that i think its correct

workers of lowell mills were greatly benefited for the waltham type of work which was more a paternalist kind, trying to protect the integrity of this little girls coming from small farmers and providing an adequate place of work, this in an effort to avoid the issues of bad place conditions and immorality that the people in bigger industrialized cities of great britain were experimenting.