THE NORTH: The Army of the Potomac has shifted north to the vicinity of Manassas. On the 16th orders go out to the Cavalry Corps to aggressively push to the west to both cover a shift of the army in that direction and determine, if possible, the disposition of the rebel army. The morning of the 17th finds the cavalry moving out from Manassas. The goal is to force the pass at Aldie and push west to develop the situation. 2nd Brigade of the 2nd Cavalry Division leads the advance. The infantry forces of the Union army are well to the rear of the cavalry probe and can offer no help. THE SOUTH: The Confederate cavalry moves out on the 15th to screen the transit of 1st and 3rd Corps to the Valley. Fitz Lee's brigade leads the advance followed by Robertson's and W.H.F. Lee's commands. The rest of the horse will follow as the infantry makes its way behind the screen. By the 17th commands of the two Lees reconnoiter toward Aldie and Thoroughfare Gap, while Robertson is centrally located at Rectortown to act as support for the advance forces. By mid afternoon Fitz Lee's command is resting between Middleburg and Aldie while pushing skirmishers forward and W.H.F. Lee's brigade is probing Thoroughfare Gap. The 15th Virginia is cooperating with 3rd Corps in its movement. Hampton's and Jones' brigades screen the upper Rappahannock. None of these units are due to link up with the rest of the cavalry until after 3rd Corps is safely in the Valley - a matter of several days. Full breakdown of units is used in this scenario.
