I do recall reading an account of a "Cherokee Freedman", who was a company commander in the 1st Cherokee Mounted Rifles (CS), aka Drew's Regiment. He apparently, led his company at Pea Ridge. The regiment ultimately "defected" during the 1st Invasion of the Indian Territory in the summer of 1862. The Freedmen from this unit, were the core of the 1st Kansas Colored Infantry (US), aka 79th USCT. The full and mixed-blood, non-Afriamerindians, went into the 2nd and 3rd Indian Home Guard Regiments (US).
Twenty-two (22) of my Cherokee and mixed-blood ancestors were members of the 1st and 2nd Cherokee Mounted Volunteers (CS). I do have a third-cousin who is mixed African and European American. We share a mixed-blood Cherokee gg-grandfather.