Growing up in Crossett, I am aware of an area just sw of town that had been a small community called Petersburg. Even in the 1960's and 1970's there was nothing but pine trees out there. If it existed during the war, I'm not sure. I remember seeing it on a map of Arkansas from the 1880's or 1890's. It was there before Crossett.
There were several small towns that existed during the war in Ashley County that exist as no more than gravel crossroads now.
Berlin comes to mind, which is south of Crossett near the LA line. The 3rd Arkansas had a company that I believe was called the Berlin Beauregards.
Anyway, Petersburg was just sw of town and may have been a small farming community during the WBTS.
Do you have some historical reference about the community to share?