3rd US Infantry, Fifth Army Corps

   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.