Detail from the Conferate Gilmer Map, 1863, showing the Gregory house adjacent to the Jerusalem Plank Road.

Detail from Confederate "Map of the Approaches to Petersburg and their Defenses." Gilmer, 1863. Official Atlas, plate 40:1. Gregory house is right (south) of Batteries 27 and 28 of the Dimmock Line, adjacent to the Jerusalem Plank Road.

Detail from Engineer Department Map dated July 28, 1864, site of Gregory House. (NARA) "G" marks the projected site of Fort Sedgwick.