Let us return to the Sixth Corps of the Army of the Potomac, where operations now demanded Lee's undivided skill. This was properly the left wing of the army, which, under Sedgwick, had made the demonstration below Fredericksburg, to enable the right wing, under Hooker, to cross the river above, and establish itself at Chancellorsville. It had consisted of three corps; but, so soon as the demonstration had effected its purpose, it will be remembered that Hooker withdrew from Sedgwick's command both the First and Third Corps, leaving him with his own, the Sixth, to guard the crossings of the river; while Gibbon's division of the Second Corps did provost duty at the camp at Falmouth, and held itself in readiness to move in any direction at a moment's notice.

From this time on, the Sixth Corps may be more properly considered as a detached command, than as the left wing of the Army of the Potomac.

And, beyond some demonstrations in aid of Hooker's manoeuvring, Sedgwick had been called on to perform no actual service up to the evening of May 2.

On May 1, a demonstration in support of Hooker's advance from Chancellorsville had been ordered, and speedily countermanded, on account of the despatch having reached Sedgwick later than the hour set for his advance.

On the forenoon of May 2, Hooker had given Sedgwick discretionary instructions to attack the enemy in his front, "if an opportunity presents itself with a reasonable expectation of success."

Then came the despatch of 4.10 P.M., May 2, already quoted, and received by Sedgwick just before dark:—

"The general commanding directs that Gen. Sedgwick cross the river as soon as indications will permit; capture Fredericksburg with every thing in it, and vigorously pursue the enemy. We know the enemy is flying, trying to save his trains: two of Sickles's divisions are among them."

This despatch was immediately followed by another: "The major-general commanding directs you to pursue the enemy by the Bowling-Green road."

In pursuance of these and previous orders, Sedgwick transferred the balance of the Sixth Corps to the south side of the Rappahannock, one division being already there to guard the bridge-head. Sedgwick's orders of May 1 contemplated the removal of the pontoons before his advance on the Bowling-Green road, as he would be able to leave no sufficient force to guard them. But these orders were received so late as daylight on the 2d; and the withdrawal of the bridges could not well be accomplished in the full view of the enemy, without prematurely developing our plans.

The order to pursue by the Bowling-Green road having been again repeated, Sedgwick put his command under arms, advanced his lines, and forced the enemy—Early's right—from that road and back into the woods. This was late in the evening of Saturday.

On the same night, after the crushing of the Eleventh Corps, we have seen how Hooker came to the conclusion that he could utilize Sedgwick in his operations at Chancellorsville. He accordingly sent him the following order, first by telegraph through Gen. Butterfield, at the same time by an aide-de-camp, and later by Gen. Warren:—

The major-general commanding directs that Gen. Sedgwick crosses the Rappahannock at Fredericksburg on the receipt of this order, and at once take up his line of march on the Chancellorsville road until you connect with us, and he will attack and destroy any force he may fall in with on the road. He will leave all his trains behind, except the pack-train of small ammunition, and march to be in our vicinity at daylight. He will probably fall upon the rear of the forces commanded by Gen. Lee, and between us we will use him up. Send word to Gen. Gibbon to take possession of Fredericksburg. Be sure not to fail. Deliver this by your swiftest messenger. Send word that it is delivered to Gen. Sedgwick.

At eleven P.M., when this order of ten o'clock was received, Sedgwick had his troops placed, and his dispositions taken, to carry out the orders to pursue, on the Bowling-Green road, an enemy indicated to him as in rapid retreat from Hooker's front; and was actually in bivouac along that road, while a strong picket-line was still engaged skirmishing with the force in his front. By this time the vanguard of his columns had proceeded a distance variously given as from one to three miles below the bridges in this direction; probably near the Bernard House, not much beyond Deep Creek.

It is to be presumed that the aide who bore the despatch, and reached Sedgwick later than the telegram, gave some verbal explanation of this sudden change of Hooker's purpose; but the order itself was of a nature to excite considerable surprise, if not to create a feeling of uncertainty.

Sedgwick changed his dispositions as speedily as possible, and sent out his orders to his subordinates within fifteen minutes after receipt of Hooker's despatch; but it was considerably after midnight before he could actually get his command faced about, and start the new head of column toward Fredericksburg.

Knowing the town to be occupied by the Confederates, Sedgwick was obliged to proceed with reasonable caution the five or six miles which separated his command from Fredericksburg. And the enemy appears to have been sufficiently on the alert to take immediate measures to check his progress as effectually as it could with the troops at hand.

Fredericksburg and the heights beyond were held by Early's division and Barksdale's brigade, with an adequate supply of artillery,—in all some eighty-five hundred men. Sedgwick speaks, in his testimony before the Committee on the Conduct of the War, as if he understood at this time that Early controlled a force as large as his own; but he had been advised by Butterfield that the force was judged to be much smaller than it actually was.

In his report, Early does not mention Sedgwick's advance on the Bowling-Green road, nor is it probable that Sedgwick had done more than to advance a strong skirmish-line beyond his column in that direction. Early's line lay, in fact, upon the heights back of the road, his right at Hamilton's Crossing, and with no considerable force on the road itself. So that Sedgwick's advance was skirmishing with scouting-parties, sent out to impede his march.

Early had received general instructions from Lee, in case Sedgwick should remove from his front, to leave a small force to hold the position, and proceed up the river to join the forces at Chancellorsville. About eleven A.M. on the 2d, this order was repeated, but by error in delivery (says Lee) made unconditional. Early, therefore, left Hays and one regiment of Barksdale at Fredericksburg, and, sending part of Pendleton's artillery to the rear, at once began to move his command along the plank road to join his chief.

As this manoeuvre was in progress, his attention was called to the early movements of Sedgwick, and, sending to Lee information on this point, he received in reply a correction of the misdelivered order. He therefore about-faced, and returned to his position at a rapid gait.

It is doubtful whether by daylight, and without any considerable opposition, Sedgwick could have marched the fifteen miles to Chancellorsville in the few hours allotted him. Nor is it claimed by Hooker that it was possible for Sedgwick to obey the order of ten P.M. literally; for it was issued under the supposition that Sedgwick was still on the north bank of the river. But Hooker does allege that Sedgwick took no pains to keep him informed of what he was doing; whence his incorrect assumption. To recross the river for the purpose of again crossing at Fredericksburg would have been a lame interpretation of the speedy execution of the order urged upon Sedgwick. He accordingly shifted his command, and, in a very short time after receiving the despatch, began to move by the flank on the Bowling-Green road towards Fredericksburg, Newton's division in the advance, Howe following, while Brooks still held the bridge-head.

It was a very foggy night; which circumstance, added to the fact that Sedgwick was, in common with all our generals, only imperfectly familiar with the lay of the land, and that the enemy, active and well-informed, enveloped him with a curtain of light troops, to harass his movement in whatever direction, materially contributed to the delay which ensued.

And Sedgwick appears to have encountered Early's pickets, and to have done some skirmishing with the head of his column, immediately after passing west of Franklin's Crossing, which, moreover, gave rise to some picket-firing all along the line, as far as Deep Run, where Bartlett confronted the enemy. As the outskirts of the town were entered, four regiments of Wheaton's and Shaler's brigades were sent forward against the rifle-pits of the enemy, and a gallant assault was made by them. But it was repulsed, with some loss, by the Confederates, who, as on Dec. 13, patiently lay behind the stone wall and rifle-pits, and reserved their fire until our column was within twenty yards. Then the regiments behind the stone wall, followed by the guns and infantry on the heights, opened a fire equally sudden and heavy, and drove our columns back upon the main body. The assault had been resolute, as the casualties testify, "one regiment alone losing sixty-four men in as many seconds" (Wheaton); but the darkness, and uncertainty of our officers with regard to the position, made its failure almost a foregone conclusion. This was about daylight. "The force displayed by the enemy was sufficient to show that the intrenchments could not be carried except at great cost." (Sedgwick.)

The officer by whom the order to Sedgwick had been sent, Capt. Raderitzchin, had not been regularly appointed in orders, but was merely a volunteer aide-de-camp on Gen. Hooker's staff.

Shortly after he had been despatched, Gen. Warren requested leave himself to carry a duplicate of the order to Sedgwick, (Capt. Raderitzchin being "a rather inexperienced, headlong young man,") for Warren feared the "bad effect such an impossible order would have on Gen. Sedgwick and his commanders, when delivered by him." And, knowing Warren to be more familiar with the country than any other available officer, Hooker detached him on this duty, with instructions again to impress upon Sedgwick the urgent nature of the orders. Warren, with an aide, left headquarters about midnight, and reached Sedgwick before dawn.

As daylight approached, Warren thought he could see that only two field-pieces were on Marye's heights, and that no infantry was holding the rifle-pits to our right of it. But the stone-wall breastworks were held in sufficient force, as was demonstrated by the repulse of the early assault of Shaler and Wheaton.

And Warren was somewhat in error. Barksdale, who occupied Fredericksburg, had been closely scanning these movements of Sedgwick's. He had some fourteen hundred men under his command. Six field-pieces were placed near the Marye house. Several full batteries were on Lee's hill, and near Howison's. And, so soon as Fredericksburg was occupied by our forces, Early sent Hays to re-enforce Barksdale; one regiment of his brigade remaining on Barksdale's right, and the balance proceeding to Stansbury's.

For, at daylight on Sunday, Early had received word from Barksdale, whose lines at Fredericksburg were nearly two miles in length, that the Union forces had thrown a bridge across the river opposite the Lacy house; and immediately despatched his most available brigade to sustain him.

Early's line, however, was thin. Our own was quite two and a half miles in length, with some twenty-two thousand men; and Early's eighty-five hundred overlapped both our flanks. But his position sufficiently counterbalanced this inequality. Moreover his artillery was well protected, while the Union batteries were quite without cover, and in Gibbon's attempted advance, his guns suffered considerable damage.

Brooks's division was still on the left of the Federal line, near the bridge-heads. Howe occupied the centre, opposite the forces on the heights, to our left of Hazel Run. Newton held the right as far as the Telegraph road in Fredericksburg.

Gibbon's division had been ordered by Butterfield to cross to Fredericksburg, and second Sedgwick's movement on the right. Gibbon states that he was delayed by the opposition of the enemy to his laying the bridge opposite the Lacy house, but this was not considerable. He appears to have used reasonable diligence, though he did not get his bridge thrown until daylight. Then he may have been somewhat tardy in getting his twenty-five hundred men across. And, by the time he got his bridge thrown, Sedgwick had possession of the town.

It was seven A.M. when Gibbon had crossed the river with his division, and filed into position on Sedgwick's right. Gibbon had meanwhile reported in person to Sedgwick, who ordered him to attempt to turn the enemy's left at Marye's, while Howe should open a similar movement on his right at Hazel Run. Gens. Warren and Gibbon at once rode forward to make a reconnoissance, but could discover no particular force of the enemy in our front. Just here are two canals skirting the slope of the hill, and parallel to the river, which supply power to the factories in the town. The generals passed the first canal, and found the bridge across it intact. The planks of the second canal-bridge had been removed, but the structure itself was still sound.

Gibbon at once ordered these planks to be replaced from the nearest houses. But, before this order could be carried out, Warren states that he saw the enemy marching his infantry into the breastworks on the hill, followed by a battery. This was Hays, coming to Barksdale's relief. But the breastworks contained a fair complement before.

Gibbon's attempt was rendered nugatory by the bridge over the second canal being commanded from the heights, the guns on which opened upon our columns with shrapnel, while the gunners were completely protected by their epaulements. And a further attempt by Gibbon to cross the canal by the bridge near Falmouth, was anticipated by the enemy extending his line to our right.

Gen. Warren states that Gen. Gibbon "made a very considerable demonstration, and acted very handsomely with the small force he had,—not more than two thousand men. But so much time was taken, that the enemy got more troops in front of him than he could master."

Gen. Howe had been simultaneously directed to move on the left of Hazel Run, and turn the enemy's right; but he found the works in his front beset, and the character of the stream between him and Newton precluded any movement of his division to the right.

By the time, then, that Sedgwick had full possession of the town, and Gibbon and Howe had returned from their abortive attempt to turn the enemy's flanks, the sun was some two hours high. As the works could not be captured by surprise, Sedgwick was reduced to the alternative of assaulting them in regular form.

It is not improbable that an earlier attack by Gibbon on Marye's heights, might have carried them with little loss, and with so much less expense of time that Sedgwick could have pushed beyond Salem Church, without being seriously impeded by troops sent against him by Gen. Lee.

And, as the allegation of all-but criminal delay on the part of Gen. Sedgwick is one of the cardinal points of Hooker's self-defence on the score of this campaign, we must examine this charge carefully.

Sedgwick asserts with truth, that all despatches to him assumed that he had but a handful of men in his front, and that the conclusions as to what he could accomplish, were founded upon utterly mistaken premises. Himself was well aware that the enemy extended beyond both his right and left, and the corps knew by experience the nature of the intrenchments on the heights.

Moreover, what had misled Butterfield into supposing, and informing Sedgwick, as he did, that the Fredericksburg heights had been abandoned, was a balloon observation of Early's march to join Lee under the mistaken orders above alluded to. The enemy was found to be alert wherever Sedgwick tapped him, and his familiarity with every inch of the ground enabled him to magnify his own forces, and make every man tell; while Sedgwick was groping his way through the darkness, knowing his enemy's ability to lure him into an ambuscade, and taking his precautions accordingly.