Final answer:
The shared belief about American Indians was that they were uncivilized and required enlightenment to the ways of American society. This viewpoint caused significant cultural disruption for Native tribes. However, legislation from the mid-20th century onwards has aimed to restore tribal autonomy and preserve indigenous cultures.
Step-by-step explanation:
The belief that the two men shared about American Indians is best reflected by the commonly held notion of the time that American Indians were not civilized or educated in the ways of the world. This view considered Native American tribes as 'uncivilized', 'barbaric', and 'heathen', necessitating the duty of American society to 'enlighten' them and bring them into a 'civilized' state fitting the American image. Such ideologies led to actions that severely affected native culture and traditions, including making it illegal for tribes to practice their traditional religions and forcing assimilation into American society in various aspects such as land ownership, education, religion, and language.
Over time, policies began to shift, particularly in the 20th century, with the advent of acts like the Indian Civil Rights Act of 1968 and the Indian Self-Determination Act of 1975, recognizing tribal governments and granting them more power. These efforts signaled a transition from assimilation policies to those supporting tribal autonomy and the preservation of native cultures.