The monument to Pennsylvania's Battery D at Antietam is on Branch Avenue. (39.451086° N, 77.740029° W; see map) It was dedicated on September 17, 1904.
The battery was commanded by Captain George W. Durell for its entire three years of service. At Antietam, after crossing Burnside's Bridge it was engaged for over two hours, finally being withdrawn when its ammunition was exhausted.
From the monument:
2nd Brigade 2nd Division
posted 375 yards South
70 Degrees East
Casualties at Antietam
Recruited in Berks and Bucks Counties
Battles participated in
Kelly's Ford Jackson
Bristoe Station Wilderness
Second Bull Run Spotsylvania
South Mountain The Crater
Antietam Ream's Station
White Sulphur Springs Poplar Spring Church
Fredericksburg Fort Stedman
Vicksburg Assault on Petersburg
The symbol of the Ninth Army Corps, an intertwined anchor and cannon in a shield, is on the front of the monument.