The marker for Longstreet’s Command is on the south side of the Boonsboro Pike in front of the National Cemetery. (National Cemetery tour map)

From the marker:

C.S.A.

Longstreet’s Command 

Major General James Longstreet, Commanding

September 14-16, 1862.

Longstreeet’s Command, consisting of D.R. Jones’ and Hood’s Divisions and Evans’ Brigade with D.H. Hill’s Division of Jackson’s Command, withdrew from its position on South Mountain during the night of September 14, and marched by the Boonsboro Pike to Sharpsburg. It crossed the Antietam at the Middle Bridge and, reaching the field at about noon of September 15, formed line outside the town, its left resting on the Boonsboro Pike at this point where where it connected with the division of D.H. Hill of Jackson’s Command. Its right extended beyond the town in the direction of the Burnside Bridge.

No. 303.