Pvt. Andrew Jackson Dunn served in the "Tippah Highlanders," Co. F of the 3rd Battalion Mississippi Infantry. The information on the 3rd Battalion can be found in "The Third Battalion Mississippi Infantry and the 45th Mississippi Regiment: A Civil War History," by David Williamson. It will certainly give you a renewed appreciation of all your ancestor went through. The url below shows the book and some basic info with a bit of a description of what they went through. Hope this helps! My great-great-grandfather was also in The Third Battalion Mississippi Infantry (in Company E) and I am always happy to "meet" someone else whose ancestor went through what they did!