Numbers 38. Report of Colonel William L. Sanderson, Twenty-third Indiana Infantry.

HDQRS. TWENTY-THIRD REGIMENT INDIANA VOLS., In the Field, near Pittsburg, March 10, 1862.

SIR; I herewith submit a report of the part taken by the Twenty-third Regiment, under my command, in the battle of Pittsburg. Early in the morning of the 6th (Sunday) I received orders from Acting Brigadier-General Thayer, commanding Second Brigade, to which the Twenty-third is attached, to hold myself in readiness to march at a moment's warning. At 12 o'clock m. took up the line of march, and arrived at Pittsburg at 6 o'clock p. m., where we lay upon our arms in line of battle that night in a drenching rain. At sunrise of the 7th i was directed to move my regiment by the right about 100 rods, and then by the left flank, which placed me on the right of the First Nebraska, the left of which regiment rested on Thompson's battery (Indiana), which had been put in position during the night in our front. We remained in this position until the enemy's battery was silenced by Thompson's. Our line was then ordered forward by General Thayer, across a deep ravine and up a steep hill. There our brigade changed direction by a left half wheel. We then moved steadily forward, in line of battle, under a heavy fire. Emerging from the timber, we came into an open field, and were then moved by the right flank about half a mile. We remained in this position half an hour, when another battery of the enemy was silenced. We then moved by the right flank, in order to prevent a flank movement by the enemy. After advancing half a mile I received orders from General Thayer to move still farther to the right and attack a body of cavalry that was observed in force in the act of charging upon us, their design evidently being to turn our flank. Before getting into position they fired upon us. At the same time I opened fire with tremendous effect, which caused them to waver, and after five or six well-directed rounds they fled in utter confusion and with heavy loss. The brigade was then moved steadily forward by General Thayer in line of Battle, driving the enemy before us for nearly half a mile, when they again made desperate stand. After two hours' hard fighting the enemy retreated. The fire of my regiment being directed obliquely to the left, and that of the First Nebraska directed to the front, told with terrible effect upon the enemy.

A short time before the final retreat of the enemy, Buell's battery, under command of Lieutenant Thurber, was brought forward and rendered us considerable aid. We followed the enemy about 1 1/2 miles, and then halted and remained under arms during the night in a hard rain. During the day Company A, in command of First Lieutenant Thomas Kremenz; Company A, in command of Lieutenant Dorrough, and Company G, A Tubbs, were alternately throw, out as skirmishers, and performed their duties to my entire satisfaction.

i am much indebted to Lieutenant Colonel D. C. Anthony for his assistance during the day. He was with his regiment from the opening to the closing of the fight, and had his horse killed under him during the action. Also to Major W. p. Davis, for the prompt and efficient manner in which he executed all my orders. He acted with that coolness and bravery which characterize a true soldier. And now to my gallant adjutant, E. Commander, who was equal to every emergency, and performed all the duties pertaining to his office in carrying out my orders strictly and promptly as becomes a soldier. Captains H. C. Ferguson, Company I; Alonzo Tubbs, Company G; John S. Davis, jr., Company