From the monument:
Army of the Potomac
Battery I First U.S. Artillery
Six 12 Pounders
Lieut. George A. Woodruff commanding
Lieut. Tully McCrea commanding.
July 2&3. Arrived and took position in Ziegler’s Grove on the left of Evergreen Cemetery. Actively engaged and assisted in repelling Longstreet’s Assault. Lieut. Woodruff was mortally wounded on the 3d and the command devolved on Lieut. Tully McCrea.
Casualties: killed 1 man, wounded 1 officer and 28 men