Chancellorsville and Gettysburg | Page 9

Corps between the Eleventh and Twelfth, as he thought the interval too great there.
As soon as Jackson was en route, Lee began to demonstrate against our centre and left, to make Hooker believe the main attack was to be there, and to prevent him from observing the turning column in its progress toward the right. A vigorous cannonade began against Meade, and a musketry fire was opened on Couch and Slocum; the heaviest attack being on Hancock's position, which was in advance of the main line.
In spite of every precaution, Jackson's column as it moved southward was seen to pass over a bare hill about a mile and a half from Birney's front, and its numbers were pretty accurately estimated. General Birney at once reported this important fact at General Hooker's headquarters. It is always pleasant to think your adversary is beaten, and Hooker thought at first Jackson might be retreating on Gordonsville. It was evident enough that he was either doing that or making a circuit to attack Howard. To provide for the latter contingency the following order was issued:
HEADQUARTERS ARMY OF THE POTOMAC CHANCELLORSVILLE, Va., May 2, 1863, 9.30 A.M. MAJOR-GENERAL SLOCUM AND MAJOR-GENERAL HOWARD:
I am directed by the Major-General Commanding to say that the disposition you have made of your corps has been with a view to a front attack by the enemy. If he should throw himself upon your flank, he wishes you to examine the ground and determine upon the positions you will take in that event, in order that you may be prepared for him in whatever direction he advances. He suggests that you have heavy reserves well in hand to meet this contingency. The right of your line does not appear to be strong enough. No artificial defences worth naming have been thrown up, and there appears to be a scarcity of troops at that point, and not, in the General's opinion, as favorably posted as might be.
We have good reason to suppose that the enemy is moving to our right. Please advance your pickets for purposes of observation as far as may be safe, in order to obtain timely information of their approach.
(Signed) JAMES H. VAN ALLEN, Brigadier-General and Aide-de-camp.
For what subsequently occurred Hooker was doubtless highly censurable, but it was not unreasonable for him to suppose, after giving these orders to a corps commander, that they would be carried out, and that minor combats far out on the roads would precede and give ample notice of Jackson's approach in time to reinforce that part of the line.
When the enemy were observed, Sickles went out with Clark's battery and an infantry support to shell their train. This had the effect of driving them off of that road on to another which led in the same direction, but was less exposed, as it went through the woods. A second reconnoissance was sent to see if the movement continued. Sickles then obtained Hooker's consent to start out with two divisions to attack Jackson's corps in flank and cut if off from the main body.
Sickles started on this mission at 1 P.M. with Birney's division, preceded by Randolph's battery. As Jackson might turn on him with his whole force, Whipple's division of his own corps reinforced his left, and Barlow's brigade of the Eleventh Corps his right. He was greatly delayed by the swamps and the necessity of building bridges, but finally crossed Lewis Creek and reached the road upon which Jackson was marching. He soon after, by the efforts of Berdan's sharpshooters, surrounded and captured the 23d Georgia regiment, which had been left to watch the approaches from our lines. Information obtained from prisoners showed the Jackson could not be retreating, and that his object was to strike a blow somewhere.
Birney's advance, and the capture of the 23d Georgia were met by corresponding movements on the part of the enemy. A rebel battery was established on the high ground at the Welford House, which checked Birney's progress until it was silenced by Livingston's battery, which was brought forward for that purpose. Pleansonton's cavalry was now sent to the Foundry as an additional reinforcement. Sickles' intention was to cut Jackson off entirely from McLaws' and Anderson's divisions, and then to attack the latter in flank, a plan which promised good results. In the mean time Pleasonton's cavalry was sent forward to follow up Jackson's movement. Sickles requested permission to attack McLaws, but Hooker again became irresolute; so this large Union force was detained at the Furnace without a definite object, and the works it had occupied were vacant. While Sickles was not allowed to strike the flank, Slocum's two divisions under Geary and Williams were sent to push back the fortified front of the enemy in the woods; a much more difficult operation. Geary attacked