Final answer:
Indigenous peoples who engaged in traditional ceremonies were vulnerable to imprisonment as a result of policies that prohibited such practices before the enactment of the American Indian Religious Freedom Act of 1978. Later movements, like the International Decade of the World's Indigenous People, have sought to protect Indigenous rights including the retention of their cultures and languages.
Step-by-step explanation:
Those found to be engaged in ceremonies would be vulnerable to imprisonment under policies or laws that suppress Indigenous ceremonies, such as the ones that were in place prior to the American Indian Religious Freedom Act of 1978. This suppression reflects the historical context of colonization, where many Indigenous practices were outlawed in an attempt to assimilate Indigenous peoples into the dominant culture. For instance, various pieces of U.S. legislation historically aimed to suppress Indigenous culture before this act, acts like the Dawes Act sought to assimilate Indigenous peoples and undermine their traditional ways of life by dividing communal lands. The International Decade of the World's Indigenous People beginning in 1994, and other movements, have aimed at protecting the rights of Indigenous peoples, enabling them to maintain their cultures and languages, and supporting their self-determination.