Benjamin's battery, was Rodman's division, with Scammon's brigade in support; General Willcox's division was held in reserve. The whole command bivouacked in these positions in three lines on the night of the 16th.

On the morning of the 17th the enemy opened a heavy artillery fire on our lines, but did us little harm. Our batteries were soon brought to bear on their batteries, which were soon silenced and two of his caissons blown up.

About this time I received and order from the general commanding to make my dispositions to carry the stone bridge over the Antietam nearly opposite our center, but to await further orders before making the attack. I accordingly threw my lines forward.

The disposition of the troops at this time was as follows: General Crook's brigade and General Sturgis' division immediately in front of the bridge and the ford, a short distance above, their front covered by the Eleventh Connecticut, Colonel H. W. Kingsbury, thrown out as skirmishers; General Rodman's division, with Scammon's brigade in support, opposite the ford, some three-quarters of a mile below the bridge; General Willcox's division in the woods at the left of Benjamin's battery, in rear of the other lines. Benjamin's battery retained its original position, and the following batteries were placed in advance on his right and left, those on the left overlooking the bridge and the heights above it; Clars's and Durell's on the right; Muhlenberg's Cook's, and McMullin's on the left, and one section of Simmonds' with Crook's brigade and one section with Benjamin's battery. The battery of Dahlgren boat howitzers, attached to the Ninth New York, covered the crossing of Rodman's division at the ford below.

At 10 o'clock I received an order from the general commanding to make the attack. i directed Colonel Kingsbury, of the Eleventh Connecticut, to move forward with his line of skirmishers, and directed General Cox to detail General Crook's brigade to make the assault. General Rodman was directed to cross over at the ford below the bridge, and join on to the left of the command, which was to be thrown over the bridge. From General Crook's position it was found to be almost impossible to carry the bridge, and General Sturgis was ordered to make a detail from his division for that purpose. He immediately sent forward the Second Maryland (Lieutenant-Colonel Duryea) and the Sixth New Hampshire (Colonel Griffin), which regiments made several successive attacks in the most gallant style, but were driven back by the galling fire of the enemy. I then directed the batteries on the left to concentrate their fire on the woods above the bridge, and sent word to General Sturgis to detail the Fifty-first Pennsylvania (Colonel Hartranft) and the Fifty-first New york (Colonel Potter) to assault the bridge and carry it at all hazards. In the mean time Colonel Crook had brought a section of his battery to bear upon the heights just above the bridge. General Sturgis, by a judicious posting of these two regiments in rear of a spur which fronted the bridge, succeeded in protecting them from the enemy's fire until they reached the crest of the spur, at which point they commenced their charge and carried the bridge at the point of the bayonet at about 1 o'clock, the whole division following immediately.

The regiments separated at the head of the bridge to the right and left, and moved up the ;steep bank crowning the heights immediately beyond. Our loss at this place was fearful, the enemy being posted in rifle-pits and behind barricades, within easy musket range of our men, and almost entirely concealed and covered from our shots. We lost at