It may appear that your ancestor may have had some important ties. "september 25, 1857 | James Buchanan invitation, extended to J. S. Cunningham, who would later serve in the 1st Tennessee Cavalry Co. until his capture in the last year of the Civil War. Buchanan Presidential reception print by Harper's........" This came from the book The President's Table: Two Hundred Years of Dining and Diplomacy - Page 19. I really can't donate more than a few mintues of time because of my work with Camp Chase. As I recall I believe he was captured in Virginia in 1864. I hope this may lead to further results for you. Thx Dennis