You did not specify dates of your C. McKinstry. However, I have records of O.L. McKinstry who was in the civil war with Co D, 42nd AL Infantry Regiment from Pickens Co, AL and served with my GG Grandfather, Josiah Wright. He later signed his pension application as Probate Judge in 1891 and marriage certificate for my Grandfather in 1896. I feel quite sure he in 1870/1880 and 1900 census of Pickens Co, AL.