Question

reading check identify supporting details why did the sioux war of 1876 begin?

Explanation:

The Sioux War of 1876 was mainly triggered by the U.S. government's encroachment on Sioux - controlled lands, especially after the discovery of gold in the Black Hills. The government tried to force the Sioux onto smaller reservations, which led to conflict.

Answer:

The U.S. government's encroachment on Sioux - controlled lands, especially after the discovery of gold in the Black Hills and attempts to force the Sioux onto smaller reservations led to the war.