This marker is one of the roughly two dozen that have disappeared over the years, but records provide its location and text. It was on the south side of Boonsboro Pike, northeast of the Middle Bridge.
No image available
From the marker:
U.S.A.
Artillery Reserve, Fifth Army Corps
Lieut. Col. William Hays, Commanding.
Organization.
Battery A. 1st Battalion New York Light
Battery B. 1st Battalion New York Light
Battery C. 1st Battalion New York Light
Battery D. 1st Battalion New York Light
5th New York Battery
Battery K. 1st United States Artillery
Battery G. 4th United States Artillery
(September 15-18, 1862.)
The Reserve Artillery, following Sykes’ Division of the Fifth Army Corps, reached this point during the night of September 15. On the morning of September 16 several Batteries were placed in position on the heights overlooking Antietam Creek. Later in the day this line of Batteries was extending to the left so as to cover the approaches to the field from Harpers Ferry. This position was occupied until the close of the battle.
No. 23.