File:Vicksburg Battlefield Mississippi.jpg

English: Map of battlefield core and study areas.

Revisions to the Study Area include addition of the historic Mississippi River to reflect movements of the Federal Navy from Young’s Point north toward and around De Soto Point, and south beyond Grant’s Canal. Revisions also include addition of the Yazoo River north to Snyder’s Bluff, and the location of a Federal supply depot and its accompanying fortifications. Expansion of the Study Area around the City of Vicksburg includes the Confederate fortifications across from Grant’s Canal in the south, and fortifications north of the city on Walnut Bluff.

The Core Areas representing locations of Federal land assaults on May 19 and May 22 were expanded slightly to include the approach route of Federal forces toward the Railroad Redoubt. Core Areas associated with riverside fortifications were expanded greatly to include areas of artillery fire between the Federal Navy land batteries on Desoto Point and Confederate batteries below Vicksburg.

The ABPP added new Core Areas at the Marine Hospital battery, Walnut Bluff fortifications, and along the heights south of the city, to represent locations of fighting between the Federal Navy and Confederate land batteries. Finally, a Core Area was added on Desoto Point to include the location of the Federal Army batteries that fired from the point into the city.