All I have on William Vann was that he enlisted in 14 November 1862 at Camp Reeves, near Ft Worth and was sick. Location not stated, but I would assume in route to Mississippi. 9th left Mississippi in February for Tennessee. Mar to Jul William was a nurse at a hospital, not stated. The hospitals associated with the 9th were in Mississippi and Columbus Tennessee. There is no other information or records other than he re-enlisted in July 1863. Stephen Kirk found the same in his book on the 9th. Where did you find that they fought so close together at Kennasaw? Kirk even left him out of his new book "Line of Battle". The Brigade was in the line often during the battles of the Atlanta Campaign. They might well have fought close as you have stated. I find my kin were often close in battle, some as you state, Texas and Georgia in the line. But Union Tennessee and Indinia troops were often opposing and I had kin in that line. I wonder if they knew they were fighting each other.