About this time I received a dispatch from General Butterfield, directing me to report immediately to you at Chancellorsville, and I turned the command of the artillery over to Brigadier-General Tyler, who had just joined the army to take command of the Artillery Reserve. In the meantime the battles of May 2 and 3 had been fought at Chancellorsville. For the particulars of the service of the artillery in these battles, I respectfully refer to the reports of the commanders of the troops to which the batteries were attached. I will only note some of the main features so far as the artillery was concerned.

When the Eleventh Corps was broken up and routed, on the 2nd, its batteries are reported as having behaved well. General Pleasonton collected some batteries belonging to different corps (Martin's Horse Artillery, Sixth New York, six 3-inch guns; Clark's, B, First New Jersey, six 10-pounders; Lewis', Tenth New York, six light 12-pounders; Turnbull's, F, and K, Third United States, six 12-pounders), and with them formed a large battery of twenty-four guns. The retreating troops swept through and around this battery, carrying off horses and caissons and even overturning one of the guns; but, as a whole, it held firm, and when the enemy, flushed with success, appeared before it, met them with a storm of canister, first checking and then driving them back into the woods, from which they had emerged at 300 yards distance. It was a desperate combat between artillery and infantry at 300 yards distance, in which the artillery repulsed the infantry, flushed, as they were, with a great success, which they were following up when checked by this battery.

After being driven back, the troops of the enemy (Jackson's corps) tried by two flank movements to dislodge the battery and resume their advance. The first was repulsed by the artillery alone, the second by the artillery aided by the advance of Whipple's and Birney's divisions, which were enabled to reach the ground by the check previously given to the enemy. At the same time a battery of thirty-eight guns (Dimick's, H, First United States, six 12-pounders; Crosby's, F, Fourth [U. S.] Artillery, four 12-pounders; Winegar's, M, First New York, six 10-pounders; Fitzhugh's, K, First New York, four 3-inch guns; Thomas', C, Fourth [U. S.] Artillery, four 12-pounders; Winslow's, D, First New York, six 12-pounders; Hill's, C, First [West
Virginia, one section, two 3-inch guns; Dilger's, I, First Ohio, six 12-pounders -- Dilger relieved on Sunday morning, May 3, by Hampton's Third Pennsylvania, six 10-pounder Parrotts) was assembled near Fairview by Captain Best, Fourth U. S. Artillery, and stationed so as to reach the enemy by firing over the heads of our own troops, distant 500 yards, as no better position could be obtained, and the use of the guns was imperative. The firing was very effective, and, as far as known, without accident to our own troops. Down to 10 p. m. the cannonade was at times terrific, and contributed much to checking the enemy. The batteries were then in trenched.

Early next morning (Sunday, the 3rd), the enemy renewed the attack, and the battery replied. An open field, about three-fourths of a mile to the left and front of the battery, occupied by one of our brigades and some guns, was taken possession of by the enemy, who opened with artillery on Best's position with fearful effect, killing, among others, Captain Hampton, of the Third Pennsylvania Battery, blowing up one of the caissons, and enfilading our line of infantry. Best, however, stood to his work manfully till about 9 a. m., when, the infantry having retired, both flanks of the battery being turned, the enemy's musketry picking off men and horses, and the ammunition nearly expended, the guns were withdrawn, to save them.