arguments with the government in Washington, demanding that the forces defending the capital city report to him. The army started with relatively low morale, a consequence of its defeats on the Peninsula and at Second Bull Run, but upon crossing into Maryland, their spirits were boosted by the "friendly, almost tumultuous welcome" that they received from the citizens of the state. Although he was being pursued at a leisurely pace by Maj. Gen. George B. McClellan and the Union Army of the Potomac, outnumbering him more than two to one, Lee chose the risky strategy of dividing his army to seize the prize of Harpers Ferry. While the corps of Maj. Gen. James Longstreet drove north in the direction of Hagerstown, Lee sent columns of troops to converge and attack Harpers Ferry from three directions. The largest column, 11,500 men under Jackson, was to recross the Potomac and circle around to the west of Harpers Ferry and attack it from Bolivar Heights, while the other two columns, under Maj. Gen. Lafayette McLaws (8,000 men) and Brig. Gen. John G. Walker (3,400), were to capture Maryland Heights and Loudoun Heights, commanding the town from the east and south. The Army of the Potomac reached Frederick, Maryland, on September 13. There, Cpl. Barton Mitchell of the 27th Indiana Infantry discovered a mislaid copy of the detailed campaign plans of Lee's army—Special Order 191—wrapped around three cigars. The order indicated that Lee had divided his army and dispersed portions geographically, thus making each subject to isolation and defeat in detail. Upon realizing the intelligence value of this discovery, McClellan threw up his arms and exclaimed, "Now I know what to do!" He waved the order at his old Army friend, Brig. Gen. John Gibbon, and said, "Here is a paper with which if I cannot whip Bobbie Lee, I will be willing to go home." He telegraphed President Lincoln: "I have the whole rebel force in front of me, but I am confident, and no time shall be lost. I think Lee has made a gross mistake, and that he will be severely punished for it. I have all the plans of the rebels, and will catch them in their own trap if my men are equal to the emergency. ... Will send you trophies." McClellan waited 18 hours before deciding to take advantage of this intelligence. His delay squandered the opportunity to