Remember Sell's Store? Muriel says the source for the notes she had was a manuscript in the National Archives "Statement relative to the Exodus of Hopoith-la-yo-ho-la and his followers from the Creek and Cherokee country in the fall and winter of 1861 and 1862" It was signed by some Cherokee, Creek and Yuchi.
She says a photostat of this paper is in Civil War File 1861, Editorial Department, OHS.
I would really like to have a copy.