Answer:
For the documentation of the experiment in civilizing the Indian children
Step-by-step explanation:
Carlise Indian School was established with the initial purpose of educating the American Indian children. Also, the goal was to take in those American Indian children into the mainstream European American culture.
The photograph taken before and after the enrollment in Carlise Indian school would help to document the changes in the children in terms of the culture like clothing, posture, hygiene, etc.
Since the photograph could be used to easily observe the change in children, it was used to document the experiment in civilizing the Indian children.