The monument to the 1st Regular Brigade, Artillery Reserve, Army of the Potomac is south of Gettysburg on Hancock Avenue. (39.80733° N, 77.235575° W; Google map; Tour map: Hancock Avenue Part 2)

Monument to the 1st Regular Brigade, Artillery Reserve, Army of the Potomac

From the monument:

Army of the Potomac 
Artillery Reserve
First Regular Brigade
Capt. Dunbar R. Ransom

1st U. S. Battery H
Lieut. Chandler P. Eakin Lieut. Philip D. Mason
July 2. And 3. Engaged on Cemetery Hill.

3d U. S. Batteries F and K
Lieut. John G. Turnbull
July 2. Engaged on Emmitsburg Road on right of the Smith House.
July 3. On and near Cemetery Ridge.

4th U. S. Battery C
Lieut. Evan Thomas
July 2 and 3. Engaged on Cemetery Ridge on left of Second Corps.

5th U. S. Battery C
Lieut. Julian V. Weir
July 2 and 3. Engaged on Cemetery Ridge and in front on left of Second Corps.

Casualties Killed 1 Officer 12 Men Wounded 4 Officers 49 Men Captured or Missing 2 Men Total 68

Monument to the Headquarters of the 1st Regular Brigade of the Artillery Reserve of the Army of the Potomac at Gettysburg