The monument to the First Brigade Horse Artillery of the Cavalry Corps is south of Gettysburg on Pleasonton Avenue. (Tour map: Pleasonton Avenue

Monument to the 1st Brigade, Horse Artillery, Cavalry Corps of the Army of the Potomac at Gettysburg

The photo looks north from Pleasonton Avenue. The car in the distance is on Taneytown Road. The 1st Ohio Cavalry monument is on the upper right.

From the monument:

Army of the Potomac 
Cavalry Corps Horse Artillery
First Brigade 
Capt. James M. Robertson
 

9th Michigan Battery
Capt Jabez J. Daniels

July 3. Engaged on Cemetery Ridge south of Pleasonton Avenue subject to the orders of Major Gen. J. Newton.

6th New York Battery
Capt. Joseph W. Martin
In Reserve

2d U. S. Batteries B and L
Lieut. Edward Heaton
In Reserve

2d U. S. Battery M
Lieut. A. C. M. Pennington Jr.

July 3. With the Cavalry on the right.

4th U. S. Battery E
Lieut. Samuel S. Elder

July 3. With First Brigade Third Division on left.

Casualties Killed 2 Men
Wounded 1 Officer 5 Men Total 8