Jan Neubert Schultz 
Battle Cry [PDF ebook] 

Two boys, best friends, are torn between opposing sides of bloody war in 1862. Johnny is white, and Chaska is part Dakota. The boys have seen whites treat the Dakota with injustice and cruelty. And they have witnessed the Dakota seek revenge with violence and murder. Can Johnny and Chaska still be friends? Can they even survive? The answers are unclear as battle after battle of the Dakota Conflict tears apart their homes and the lives of everyone they love. Both boys must somehow find the strength and courage to face the terrible danger.