As Becky mentioned in her response on Monday morning, we have driven all the roads between Vicksburg and the Big Black River. The roads still exist and are mostly sunken with few improvements.
Sherman mentioned: "In order that you may understand any future communication, mark your map as follows: One and a half miles east of Young's, where the road comes in from Markham, mark Hill's; 1½ miles southeast of Hill's, Jones' plantation; 2 miles below Birdsong Ferry, Jones' Ford; 1½ miles southeast of Cameron, Messinger's plantation and Ford; 1 mile east of Fox, mark Parson Fox; 3 miles east of Tiffin, on the Bridgeport road, Brook. All these points may become of note. I still regard the country at Tiffin, Brant, Cowan, W. Wixon, and Hardaway as the key-points of this region. I still have my headquarters by the roadside, in front of Tribbs', where the road forks to Young's and Markham's."
I have overlain the Union maps from the Civil War Atlas onto modern day USGS/Google maps identify the roads and locations of markings on the maps. (I am a civil engineer and surveyor). Unfortunately, due to the hilly landscape, we have not been able to locate the exact location of Parson Fox's plantation (Sherman's camp after 4 July). I hope to go to the land ownership records in Vicksburg to find the location of Fox's land.
Becky and I have focused on Champion Hill. Again, I have overlain the Union map on modern day USGS maps and found the maps to be exceeding accurate! We believe that we have found another "old" road, previously thought to be a logging road, to be the road from the Jackson Road near the Champion house to Midway Station.