Head-Quarters Army of Northern Virginia,
September 9, 1862.
Special Orders, No. 191.
The army will resume its march to-morrow, taking the Hagerstown road. General Jackson’s command will form the advance, and, after passing Middletown, with such portion as he may select, take the route towards Sharpsburg, cross the Potomac at the most convenient point, and, by Friday night, take possession of the Baltimore and Ohio Railroad, capture such of the enemy as may be at Martinsburg, and intercept such as may attempt to escape from Harper’s Ferry.
General Longstreet’s command will pursue the same road as far as Boonsborough, where it will halt with the reserve, supply, and baggage trains of the army.
General McLaws, with his own division and that of General R. H. Anderson, will follow General Longstreet. On reaching Middletown he will take the route to Harper’s Ferry, and by Friday morning possess himself of the Maryland Heights, and endeavor to capture the enemy at Harper’s Ferry and vicinity.
General Walker, with his division, after accomplishing the object in which he is now engaged, will cross the Potomac at Cheek’s Ford, ascend its right bank to Lovettsville, take possession of Loudoun Heights, if practicable, by Friday morning, Key’s Ford on his left, and the road between the end of the mountain and the Potomac on his right. He will, as far as practicable, co-operate with General McLaws and General Jackson in intercepting the retreat of the enemy.
General D. H. Hill’s division will form the rear-guard of the army, pursuing the road taken by the main body. The reserve artillery, ordnance, supply-trains, etc., will precede General Hill.
General Stuart will detach a squadron of cavalry to accompany the commands of Generals Longstreet, Jackson, and McLaws, and with the main body of the cavalry will cover the route of the army and bring up all stragglers that my have been left behind.
The commands of Generals Jackson, McLaws, and Walker, after accomplishing the objects for which they have been detached, will join the main body of the army at Boonsborough or Hagerstown.
Each regiment on the march will habitually carry its axes in the regimental ordnance wagons, for use of the men at their encampments to procure wood, etc.
By command of General R. E. Lee
R. H. Chilton,
Assistant Adjutant-General.
Major-General D. H. Hill,
Commanding Division
Source: Official Records
Commentary
This order had been sent from both General Headquarters and Thomas "Stonewall" Jackson's headquarters to D.H. Hill's command due to Jackson's mistaken idea that Hill was still under his command. While en-route the order sent by General Headquarters and signed by Robert Chilton was lost and then found by three Federal soldiers who, realizing the possible importance of the order, sent it to their Colonel who sent it on to McClellan. No one the Army of Northern Virginia realized the order had been lost.
Longstreet's command was one of the first to feel the results of McClellan knowing all of Lee's plans. His forces encountered the Federals at South Mountain and Turner's Gap shortly before the battle of Sharpsburg got underway.