before nightfall, however, under cover of a heavy artillery
fire, the Federals pushed a force of infantry across the ford, drove
back the two brigades, which, with thirty pieces of artillery, formed
the Confederate rear-guard, and captured four guns. Emboldened by
this partial success, McClellan ordered Porter to put three brigades
of the Fifth Army Corps across the river the next morning, and
reconnoitre towards Winchester.

The news of the disaster to his rear-guard was long in reaching Lee's
headquarters. His army had not yet recovered from the confusion and
fatigue of the retreat. The bivouacs of the divisions were several
miles from the river, and were widely scattered. The generals were
ignorant of each other's dispositions. No arrangements had been made
to support the rear-guard in case of emergency. The greater part of
the cavalry had been sent off to Williamsport, fifteen miles up
stream, with instructions to cross the Potomac and delay the enemy's
advance by demonstration. The brigadiers had no orders; many of the
superior generals had not told their subordinates where they would be
found; and the commander of the rear-guard, General Pendleton, had
not been informed of the strength of the infantry placed at his
disposal. On the part of the staff, worn out by the toils and
anxieties of the past few days, there appears to have been a general
failure; and had McClellan, calculating on the chances invariably
offered by an enforced retreat, pushed resolutely forward in strong
force, success might possibly have followed.

September 20.

Lee, on receiving Pendleton's report, long after midnight, sent off
orders for Jackson to drive the enemy back. When the messenger
arrived, Jackson had already ridden to the front. He, too, had
received news of the capture of the guns; and ordering A.P. Hill and
Early,* (* Commanding Ewell's division, vice Lawton, wounded at
Sharpsburg.) who were in camp near Martinsburg, to march at once to
Shepherdstown, he had gone forward to reconnoitre the enemy's
movements. When Lee's courier found him he was on the Shepherdstown
road, awaiting the arrival of his divisions, and watching, unattended
by a single aide-de-camp, the advance of Porter's infantry. He had at
once grasped the situation. The Confederates were in no condition to
resist an attack in force. The army was not concentrated. The cavalry
was absent. No reconnaissance had been made either of lines of march
or of positions. Th