The C.S. makes agreeable treaties with the Indians in its domain, particularly those of the Indian Territory, ensuring their support for the new nation. The U.S. Army, freed up by the war's quick end, lets off steam by accelerating the U.S. settlement of the Great Plains and the West which also accelerated the Indian wars, crushing all hostile tribes by the early 1870s. (Except for the Comanche and Kiowa, who take full advantage of the new U.S.-C.S. border and manipulate the continuing hostility between the two nations to their own maximum benefit.) One result of this is that the Battle of Little Big Horn (1876 in our timeline) never happens, a divergence which will have consequences resonating throughout this series.