PART V.
_LEE INVADES MARYLAND_.
I.
HIS DESIGNS.
The defeat of General Pope opened the way for movements not contemplated, probably, by General Lee, when he marched from Richmond to check the advance in Culpepper.

His object at that time was doubtless simply to arrest the forward movement of the new force threatening Gordonsville.

Now, however, the position of the pieces on the great chess-board of war had suddenly changed, and it was obviously Lee's policy to extract all the advantage possible from the new condition of things.
He accordingly determined to advance into Maryland--the fortifications in front of Washington, and the interposition of the Potomac, a broad stream easily defended, rendering a movement in that direction unpromising.

On the 3d of September, therefore, and without waiting to rest his army, which was greatly fatigued with the nearly continuous marching and fighting since it had left the Rapidan, General Lee moved toward Leesburg, crossed his forces near that place, and to the music of the bands playing the popular air, "Maryland, my Maryland," advanced to Frederick City, which he occupied on the 7th of September.
Lee's object in invading Maryland has been the subject of much discussion, one party holding the view that his sole aim was to surround and capture a force of nine or ten thousand Federal troops stationed at Harper's Ferry; and another party maintaining that he proposed an invasion of Pennsylvania as far as the Susquehanna, intending to fight a decisive battle there, and advance thereafter upon Philadelphia, Baltimore, or Washington.

The course pursued by an army commander is largely shaped by the progress of events.