Army of Northern Virginia

   The Army of Northern Virginia was composed of Longstreet's and Jackson's Commands, Stuart's Cavalry Division and the Reserve Artillery.

D. R. Jones' and Hood's Divisions and Evans' Brigade of Jackson's Command, also D.H. Hill's Division of Jackson's Command, were withdrawn from South Mountain during the night of September 14 and concentrated at Sharpsburg early next day, September 15. McLaws', R.H. Anderson's and Walker's Divisions were detached from Longstreet's Command to assist Jackson in the investment of Harpers Ferry. Jackson's Command, having captured Harpers Ferry, reached Sharpsburg on September 16 and 17. Stuart's Cavalry and a part of the Reserve Artillery reached the field on the 15th and 16th. At nightfall of the 16th Hood's Division, occupying a position in the East Woods and in the fields between them and the Hagerstown Pike, in advance of the left of the Confederate line, encountered the advance of Meade's Division of Hooker's Corps, Army iof the Potomac. The engagement ended at dark.