Video: 'Special Orders 191'

(Saturday, September 13, 1862, at about noon local time; during the American Civil War) — Two Union soldiers, Sergeant John Bloss and Corporal Barton W. Mitchell, discovered a mislaid copy of Confederate General Robert E. Lee’s detailed Antietam battle plans today outside of Frederick, Maryland.

Special Order 191 was found wrapped around three cigars in a meadow which had served as the site of a Confederate camp a few days before.

Video: 'Ken.Burns.The.Civil.War.3of9.Forever.Free.' (Sep. 13, 1862, at 41:57)

The order indicated that Lee had divided his army and dispersed portions geographically (to Harpers Ferry, West Virginia, and Hagerstown, Maryland), thus making each subject to isolation and defeat if Maj. Gen. George B. McClellan could move quickly enough.

McClellan waited about 18 hours before deciding to take advantage of this intelligence and reposition his forces, thus squandering an opportunity to defeat Lee decisively.