In 1884, the government of Canada passed an amendment to the Indian Act which prohibited potlatch, or "the Indian dance known as Tamanawas". In 1894-95, the laws against Indigenous ceremonies were made more repressive by banning any type of 'giveaway' dances or ceremonies, and any type of ceremony that involved self-mutilation. In an 1895, amendment to the Indian Act, the Sun Dance and Thirst Dance were prohibited. This was enacted after Deputy Superintendent Lawrence Vankoughnet requested that Edgar Dewdney abolish it.
First amendment to the Indian Act restricting ceremonies was in 1884, with further restrictions put in place in 1895.
Lawrence Vankoughnet to Edgar Dewdney, 4 December 1889
The implication of these anti-potlatch laws imposed by the federal government resulted in the assimilation of Indigenous people and promoted cultural loss to befit Euro-Canadian society. While the government enacted these anti-ceremonial laws (the Potlatch, Thirst Dance, Sun Dance, etc.), Indigenous peoples continued to practice their ceremonies, however, it was criminalize, fines were used to deter participation, and the government did limit participation Practicing dances and ceremonies, much akin to non-Indigenous cultures, are integral to cultural fulfillment, a positive life, and self image/sense of self. By prohibiting Indigenous peoples from practicing their ceremonies, the government was promoting and enacting cultural genocide and white supremacy.
This prohibited Indigenous groups from engaging in Sun Dance ceremonies.