On Friday, at 11 a. m., pursuant to orders, I moved the Twelfth Corps from Chancellorsville toward Fredericksburg, on the Plank road. We met the skirmishers of the enemy about a mile from the Chancellor house; formed in line of battle and advanced, the enemy falling back toward the heights of Fredericksburg.

At about 1 p. m. orders were received to return to our original line. In this movement our loss was only 10 killed and wounded. Friday night and Saturday morning were spent in strengthening our position.

At 3.30 p. m. on Saturday, I received a note from General Sickles, stating that he was advancing a strong line of two brigades to ascertain whether the enemy was retreating; that General Birney reported that he had reached a brigade of the enemy in rifle-pits, posted, as he (General Sickles) thought, to cover the retreating column; that he would attack him if he was not stronger than reports so far represented, and occupy the road by which he was retreating, and that he desired me to support his advance. This note was at once referred to the commanding general, and, with his consent, I sent nearly all the First Division, under General Williams, to the support of General birney, and at the same time advanced a portion of the Second Division, under General Geary, to feel the enemy in its front. It soon became evident that the enemy was in force in this position and strongly posted. The Second Division was, therefore, recalled, and directed to hold its original line.

While this division was retiring as ordered, the enemy attacked the extreme right of our line, which was held by the Eleventh Corps. I at once rode in that direction; but before arriving within a mile of the line met large numbers of that corps retiring in the utmost disorder. I at once dispatched two staff officers with orders to General Williams to return as rapidly as possible this original line, hoping to make such disposition of his troops as would assist in checking the advance of the enemy. This order was promptly obeyed; but the enemy had possessed himself of the right of the line formerly occupied by General Williams before his arrival, and, in attempting to regain his position, Colonel Mathews, of the One hundred and twenty-eighth Pennsylvania Volunteers, and nearly 200 of his regiment, were captured. Williams' division at once took possession of the left of the line formerly held by him, and formed Ruger's and Knipe's brigades in line on the left of and at right angles to the Plank road leading toward the Wilderness, his right connecting with the division of General Berry, formed on the right of the Plank road.

In the meantime Captain Best, chief of artillery of the Twelfth Corps, had by great exertions got thirty-four guns in position on the crest of the hill in rear of these divisions. The divisions of General Williams and Berry, with a well-directed fire from our artillery, checked the advance of the enemy. A portion of the troops our artillery, checked the advance of the enemy. A portion of the troops under General Birney, on returning, took position on the crest of a hill nearly in prolongation of the line held by Geary's division. At about 12 o'clock Saturday night, a portion of these troops advanced against the enemy directly in front of Williams' division. As I had not been informed that a night attack was contemplated by our forces, I supposed, on hearing the firing, that the enemy were advancing on Williams's division, and at once opened upon them with our artillery. General Williams also fired upon all lines that made their appearance in his front. I have no information as to the damage suffered by our troops from our own fire, but fear that our losses must have been severe.

At daybreak on Sunday, May 3, the enemy commenced the attack