September 17 — Early this morning the cannon commenced booming on the fields around Sharpsburg in Washington County, Maryland. Sharpsburg is about three miles from Shepherdstown, and from our camp we plainly heard the opening guns of the great battle that raged fearfully all day between General Lee’s forces and General McClellan’s whole army. At times the artillery fire was so fierce and heavy that it sounded like one continual roar of thunder rumbling and rolling across the sky. The musketry fire was equally severe and raged furiously, almost incessantly all day, and its hideous deathly crash vied with the deafening roar of the thundering artillery. It is utterly incomprehensible and perfectly inconceivable how mortal men can stand and live under such an infantry fire as I heard to-day. Judging from the way the musketry roared the whole surrounding air between the lines must have been thick with flying lead. This morning my gun was still in Martinsburg undergoing repairs, which circumstance alone kept us from the battle-field to-day, for twice during the day an urgent despatch came for us to hasten to the front and help to play in the bloody act that was in full glow and raging over the fields around Sharpsburg. About three o’clock this afternoon my gun arrived from Martinsburg ready for fight, and we started immediately for the fiery vortex of battle that was still raging with unabated fury. Our progress was necessarily slow, and the ford in the Potomac is rough and narrow and the river was full of wagons going and coming. The road all the way between the river and the battle-field was crowded with ordnance wagons and ambulances. Shepherdstown seemed to be full of our wounded when we passed through. We had to go a mile below town to ford the river. Below Shepherdstown there are high bluffs along the river on the Virginia side, and right at the ford I saw a battery of artillery in position on top of the bluff, which thoroughly commanded the ford and its approaches on the Maryland side, which is much lower than the Virginia bluff. It was nearly sunset when we arrived on the battle-field and the last firing for the day had just ceased. There were a great many of the wounded still on the field. We bivouacked just in rear of the battle-field and roughed it without blankets.