Question

what were the reasons for the clashes between the U.S. government and the Sioux

Answer 1

Black Hills, in Dakota, United States, was considered sacred by the Sioux Indians, while the US Government wanted to take possession of it. This led to a series of clashes followed by negotiations between the two.

In 1868, a conference was held at Fort Laramie and a Treaty drawn, recognising the Black Hills, as part of the Great Sioux Reservation, which is set aside exclusively for the use of Sioux Indians.