The Canadian federal government, spurred by Christian missionaries, outlawed the potlatch under the Indian Act. The ban took effect in the 1870s but was not fully enforced until much later, most vociferously after 1923. Heiltsuk Chiefs were angered by the ban and the missionary interference in their traditional customs. The ban lasted until the Indian Act was amended in 1951. According to Heiltsuk oral tradition, though the ban was lifted, no one informed the Heiltsuk at the time. The missionaries saw the potlatch as the basis for Heiltsuk (and more broadly for other First Nations on what anthropologists label the Northwest Coast) social and political organization, and as the most obvious expression of non-Christian beliefs, to which they were opposed.