Bruce, I have only just begun to try and find out more about the Cumberland Hospital at Nashville, due to the fact that an acting assistant surgeon, William A. Lightbourne, was employed there in the service of the U.S. I don't know if he was a contract surgeon, but I do know that he had previously been assistant surgeon in the 25th Tennessee Infantry, of the Confederate Army, resigning in October, 1861, then being a contract surgeon at the General Hospital in Sparta, Tennessee in 1862. At some later stage, in 1864, he was then employed as a.a.s. at the Cumberland Hospital, then in the Union held city of Nashville. Being born in the United Kingdom, I guess he did not have any qualms about changing sides. He was, in January, 1864, presented with a watch and chain, and his acceptance speech seems to give praise to the side he was then working for, the Union staff and patients of the hospital. He died in New Zealand in 1894.