My husband and I are Civil War researchers and we pretty much know the area of Sherman's camp at the Big Black - and how it was in relation to Steele's Division located at the Big Black Bridge. Using a GPS and Civil War maps, we have run the roads east of Bridgeport Ferry which is where Sherman was after the fall of Vicksburg. Before the fall of Vicksburg his camp was about a mile west of Parson Fox's plantation.
I have asked my husband to respond to this. RBDrake