Special Orders 191 were the marching orders issued by General Robert E. Lee and drafted by Colonel Robert Chilton for the Army of Northern Virginia during its Philadelphia campaign in the fall of 1862. The orders were risky as they called for each division of the army to march through a different stretch of enemy territory alone while the Army of the Potomac was nearby. However, Lee correctly predicted that the Union commander, George McClellan, would be too slow and timid to challenge the Confederates even if he knew of their diffuse marching order, which he did not.