How did the union break its treaty with the five tribes when the civil war started?

a.
to create a peace treaty and resettle plains tribes on reservations
b.
to pacify plains tribes and give them land
c.
to acquire more land for white settlers
d.
to punish plains tribes that raided white settlements

to create a peace treaty and resettle (A)

Explanation:

they broke off their first treaty to create the peace treaty to have land to resettle on.

social contract theory, nearly as old as philosophy itself, is the view that persons' moral and/or political obligations are dependent upon a contract or agreement among them to form the society in which they live

where is the picture?