|Robert E. Lee|
On the evening of September 9, 1862, staff officers and couriers emanated from Lee's headquarters outside of Frederick. The riders delivered multiple copies of Special Orders No. 191 to Lee's subordinates. The orders outlined the division of the Army of Northern Virginia into multiple pieces, three of which, led by Stonewall Jackson, Lafayette McLaws, and John Walker, would take different routes to intercept, destroy, or capture the enemy garrisons at Martinsburg and Harpers Ferry. When the orders went into effect the next day, Lee anticipated that these three wings would wrap up the operations in the Valley quickly--perhaps as early as September 12--before the army reunited and continued on its trek north.