I've heard of Benjamin O. Davis, but all I know is that he was the first black general. Were there any other non-whites before him?
There were two American Indian Generals in the US Civil War (one on each side).
Stand Watie was a Cherokee leader who became a Confederate general and led two battalions of Cherokee cavalry as well as Creek, Osage and Seminole forces in several successful battles. Watie was the last Confederate General to surrender in the Civil War, two months after Robert E. Lee surrendered at Appomattox.
The only other Native American Brigadier General in the Civil War was Union General Ely S. Parker, a member of the Seneca Tribe, who drafted the articles of surrender which Lee signed.
At the surrender ceremony Robert E. Lee said to Parker, "I'm glad to see one real American here." Parker replied, "We are all Americans."