This marker is one of the roughly two dozen that have disappeared over the years, but records provide its location and text. The marker was on the south side of the Boonsboro Pike, just east of the Middle Bridge.
No image available
U.S.A.
Fifth Army Corps
Third United States Infantry
Captain John D. Wilkins, Commanding.
(September 15-19, 1862.)
On the afternoon of September 15 the 3rd U.S. Infantry was deployed as skirmishers on the crest of the ridge, on either side of the road at this point, overlooking the Antietam and the bridge.
It remained in this position until about 10 A.M. of the 16th, when it was relieved by the advance of the 4th U.S. Infantry across the bridge.
It then retired to the reserve at the eastern base of the ridge, where it remained until the morning of the 19th when it advanced to Sharpsburg.
No. 82.
See more on the history of the 3rd United States Infantry Regiment in the Civil War