Use the excerpt below to answer the question.
Treaties made in the Pacific Northwest stipulated that the U.S. government would provide education to Native Americans living on reservations. Though it took several years, day schools and
boarding schools were eventually established on reservations. In addition, boarding schools... were established off reservations. Students were required to live at boarding schools most of the
year, thereby removing them from the influence of their families and traditional cultures.
-Library of Congress
"What was the purpose of the treaties described in the excerpt?
O to encourage Native Americans to remain on reservation lands
O to pass legislation to ensure Native Americans political rights
O to promote the assimilation of Native Americans into mainstream culture
O to encourage Native Americans to retain their tribal identities and traditions