an assault. A. P. Hill formed the 2,000 men of his division into two lines of three brigades each, and attacked at around 09:00. Having advanced about beyond the river, Lovell's brigade detected the movement, and divisional commander George Sykes was informed, who authorized a withdrawal. A single Union regiment attempted to outflank Dorsey Pender's brigade, but was unsuccessful. Porter ordered a withdrawal, but the commander of the 118th Pennsylvania Infantry Regiment (nicknamed the "Corn Exchange Regiment") refused to withdraw his command, as he believed the orders had not come through the proper chain of command. The withdrawal order had been delivered through a staff officer who had given it to a lieutenant in the 118th. The 118th Pennsylvania was an inexperienced unit that had only been in the army for about three weeks, and it found out that half of the weapons it had been issued were defective. The regiment fought for about 30 minutes before being put to rout. Fleeing Union troops attempted to cross the river, but came under heavy fire while trying to withdraw. Some were shot while trying to cross a dam, while others drowned in the river. The 118th Pennsylvania suffered additional losses from artillery friendly fire as it tried to withdraw. Union artillery prevented the Confederates from crossing the Potomac, and the fighting was over by mid-morning. A small detachment from Warren's brigade recrossed the river at about 16:00 to retrieve an abandoned cannon. Hill reported after the fighting that his men had killed 3,000 Union soldiers, but the true Union casualties of the fighting were 71 dead, 161 wounded, and 131 missing. The Confederates had 30 men killed and 161 wounded; most of Hill's losses were from artillery fire. The 118th Pennsylvania alone accounted for 269 of the Union losses. Union private Daniel W. Burke was awarded the Medal of Honor in 1892 for his actions at Shepherdstown. The Confederates lost one 10-pounder Parrott rifle from Victor Maurin's Louisiana Battery, one 12-pounder howitzer from John Milledge's Georgia Battery, one 12-pounder howitzer from Marmaduke Johnson's Virginia Battery, and one 6-pounder field gun from Charles T. Huckstep's Virginia Battery. Aftermath Pendleton was widely criticized within the Confederate press and within Lee's army after the battle. The Confederate army withdrew into the Shenandoah Valley after the battle, and McClellan did not pursue. Due to his lack of aggression in pursuing the retreating Confederates, McClellan was