The following is the text of General Robert E. Lee's orders of 9 September detailing how the various parts of his army were to operate in Maryland.
A copy of these orders, intended for Division commander D. H. Hill, was found on September 13th, near Frederick, by men of the Federal 27th Indiana Regiment. There is some mystery about how the orders came to be there, but no mystery about how important they were.
MGen George McClellan, in command of the Army of the Potomac, had the authenticated orders in his posession the same day. With them, McClellan knew the disposition of his enemy in some detail, and was closer to each of the parts of the Confederate Army than they were to each other.
See more about ... the discovery of the "Lost Orders", at the 27th Indiana website.
HDQRS. ARMY OF NORTHERN VIRGINIA,
September 9, 1862.
The citizens of Fredericktown being unwilling, while overrun by members of his army, to open their stores, in order to give them confidence, and to secure to officers and men purchasing supplies for benefit of this command, all officers and men of this army are strictly prohibited from visiting Fredericktown except on business, in which case they will bear evidence of this in writing from division commanders. The provost-marshal in Fredericktown will see that his guard rigidly enforces this order.
Major Taylor will proceed to Leesburg, Va., and arrange for transportation of the sick and those unable to walk to Winchester, securing the transportation of the country for this purpose. The route between this and Culpeper Court-House east of the mountains being unsafe will no longer be traveled. Those on the way to this army already across the river will move up promptly; all others will proceed to Winchester collectively and under command of officers, at which point, being the general depot of this army, its movements will be known and instructions given by commanding officer regulating further movements.
The army will resume its march tomorrow, 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 toward Sharpsburg, cross the Potomac at the most convenient point, and by Friday morning take possession of the Baltimore and Ohio Railroad, capture such of them as may be at Martinsburg, and intercept such as may attempt to escape from Harper's Ferry.
General Longstreet's command will pursue the main road as far as Boonsborough, where it will halt, with 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 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, Keys' 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 Generals McLaws and Jackson, and intercept 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, and supply trains, &c., 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, bringing up all stragglers that may 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, &c.
By command of General R. E. Lee:
R. H. CHILTON,
R. E. LEE, General.
Thanks to "Shotgun's" ACW page for the original on-line text of these Orders.