Answer:
Between the 1940s and the 1960s the United States of America intended to transform Native Americans into western (European) civilization, what they called assimilation, with the Indian termination policy, which implied Native Americans needed to abandon their culture and shift to European culture, Activism in the 1960s was key to put pressure against the policy and led to the rise of native American rights organizations which helped produce the "Indian Self-Determination Act of 1975" fostering the Natives again, years after Nixon anounced his administration position; these events together with the "Civil Rights Movement" were key in influencing the public opinion on the issue, stirring social conscience and activism in the environment.