Meade had Sedgwick's fresh corps and was reinforced by a division of 11,000 men under General W.F.
Smith (Baldy Smith).

French's division of 4,000 at Frederick, and troops from Washington and Baltimore were also available to assist in striking the final blow.

The Twelfth Corps was also available, as Slocum volunteered to join in the pursuit.

Meade, however, delayed moving at all until Lee had reached Hagerstown and then took a route that was almost twice as long as that adopted by the enemy.

Lee marched day and night to avoid pursuit, and when the river rose and his bridge was gone, so that he was unable to cross, he gained six days in which to choose a position, fortify it, and renew his supply of ammunition before Meade made his appearance.
In consequence of repeated orders from President Lincoln to attack the enemy, Meade went forward and confronted Lee on the 12th.