Prior to the Coming of the Whites After the Civil

Prior to the coming of the whites after the Civil War, the American Indians of the Great Plains

A) had maintained their nomadic hunting way of life for thousands of years.
B) were thoroughly familiar with change, migration, and conflict.
C) lived in peace and harmony with one another.
D) relied primarily on agriculture for their sustenance.
E) were under the control of highly organized tribal governments.