The monument to the Army of the Potomac’s Artillery Reserve is south of Gettysburg on Pleasonton Avenue at the intersection with Taneytown Road. (Pleasonton Avenue tour map)

Monument to the Artillery Reserve of the Army of the Potomac at Gettysburg
Brigadier General Robert O. Tyler (West Point Class of 1853) commanded the Artillery Reserve at the Battle of Gettysburg) He was a career Army officer from New York.
From the monument
Army of the Potomac
Artillery Reserve
Brigadier General Robert O. Tyler
Captain James M. Robertson
Headquarters Guard
Thirty Second Massachusetts Infantry Co. C
Captain Josiah G. Fuller
First Regular Brigade
Captain Dunbar R. Ransom
Four Batteries
First Volunteer Brigade
Lieutenant Colonel Freeman McGilvery
Four Batteries
Second Volunteer Brigade
Captain Elijah D. Taft
Four Batteries
Third Volunteer Brigade
Captain James F Huntington
Four Batteries
Fourth Volunteer Brigade
Captain Robert H. Fitzhugh
Five Batteries
Train Guard
Fourth New Jersey (Seven Companies)
Major Charles Ewing
Casualties Killed 2 Officers 41 Men Wounded 15 Officers 172 Men Captured or Missing 12 Men Total 242
Location of the monument
The monument is south of Gettysburg on the southwest corner of Taneytown Road and Pleasonton Avenue. (39°48’27.6″N 77°13’49.9″W)