Antietam gave the federals a much-needed victory, but it didn’t have to be so difficult.
Maj. Gen. Edwin Sumner paced anxiously in front of the Pry House, Maj. Gen. George McClellan’s headquarters near Sharpsburg, as he awaited the order to move. His II Corps had been ready for battle since before dawn on September 17, 1862, but the Army of the Potomac’s commander—whom Sumner often mocked for his tendency to deploy his troops in battle “in driblets”—had held Sumner back across Antietam Creek as the Union I and XII Corps launched several disjointed and bloody attacks on the Army of Northern Virginia’s left flank.
In the first three hours of fighting around the Miller Cornfield, the Federals had managed modest success, but “Little Mac” never opted to capitalize on his advantage in numbers and attack the vulnerable Confederates with a single sledgehammer blow. Had he given his commanders rein to be more aggressive once the fighting opened at 5:15 a.m., the Federals might well have reaped an outright triumph in the Battle of Antietam, and perhaps even have destroyed Robert E. Lee’s vaunted army just three weeks after their humiliating loss at Second Bull Run.
September 17 would end as the bloodiest day in the nation’s military history. Although the Army of the Potomac could claim victory when Lee relinquished the field at nightfall and then pulled back across the Potomac to Virginia two days later, the Rebel army had remained intact enough to fight for another 21⁄2 years.
“Bull” Sumner, at 65 the Union’s oldest field commander, finally got the call to advance at 7:20 a.m., after John Bell Hood’s Division surged out of the West Woods to attack the Federals near the Cornfield. McClellan, however, committed only two of Sumner’s three divisions, keeping Maj. Gen. Israel Richardson’s unit in reserve near the Pry House until it could be relieved by one of Maj. Gen. Fitz-John Porter’s divisions. Richardson was not given the OK to move until 9 a.m., too late to help Sumner.
Sumner crossed Antietam Creek at a ford about a mile east of the Dunker Church. He pushed his two divisions, with Maj. Gen. John Sedgwick in the lead, to the East Woods and stopped to assess the situation. A chance meeting with Hooker, who had been shot in the foot about 8 a.m. and was being carried off the field, misled Sumner into believing the Federals were closer to victory than they really were. Just before 9 a.m., Sedgwick’s men marched toward the West Woods. Hood’s attack two hours earlier had been blunted with significant casualties, and Hood had retreated behind Hauser’s Ridge. Brig. Gen. Jubal Early, defending the West Woods, realized his position was threatened. Two Union brigades were moving in from the north, the 125th Pennsylvania had set up near the Dunker Church, and Capt. J.A. Monroe’s battery had unlimbered just east of the Hagerstown Pike.
As Early moved to confront the 125th Pennsylvania, he noticed reinforcements heading his way: Maj. Gen. Lafayette McLaws’ Division— which had been resting near Sharpsburg after marching from Harpers Ferry the previous day— and Col. George Thomas “Tige” Anderson’s Brigade. Also giving Early a boost was Major John Pelham’s horse artillery, which had moved from Nicodemus Hill to Hauser’s Ridge west of the church. Pelham began pummeling the 1st Minnesota as it crossed Hagerstown Pike while leading Sedgwick’s attack.
The timing of the reinforcements Robert E. Lee had sent proved critical. Sumner had designed his attack so Sedgwick’s three brigades would march in line from the East Woods directly to the northeastern corner of the West Woods. After overwhelming the Rebel defenders there, the Federals were to turn sharply left and sweep down toward Sharpsburg, a mile to the south.
Maj. Gen. William H. French’s 3rd Division was supposed to follow directly behind Sedgwick but got separated. When he reached the East Woods, French wasn’t sure which direction to head. Seeing Union troops to his left and believing they were Sedgwick’s, he ordered his men to march southwest toward a slightly sunken farm road, away from the West Woods.
As Sedgwick’s men approached the West Woods, Brig. Gen. Willis Gorman veered his lead brigade to the right. The 34th New York’s commander didn’t hear the order, however, and went left instead toward the 125th Pennsylvania as it battled Early near the Dunker Church. The 34th was able to lend the Pennsylvanians brief support there, but Gorman’s brigade, a few hundred yards to the north, was now undermanned. The other two brigades in Sedgwick’s division quickly closed ranks, but the tide had begun to turn in the Confederates’ favor.
“Tige” Anderson’s Brigade moved in behind Early. On its right were the South Carolinians in Brig. Gen. Joseph Kershaw’s Brigade and to their left were Brig. Gen. William Barksdale’s Mississippians. The 125th Pennsylvania and 34th New York were forced to retreat, as were the approaching 42nd New York and 7th Michigan. Brig. Gen. Paul J. Semmes’ had been exchanging fire with the Federals on Gorman’s front, and Early and Barksdale were now free to move against Sedgwick’s exposed left flank.
Within minutes, the Union front collapsed. Unable to locate Sedgwick—who had been wounded in the wrist, leg and shoulder— Sumner personally led his men out of the chaos back toward the East Woods, likely preventing a complete catastrophe. But the Federal casualty count for an hour or so of fighting was 2,200. A counterattack by XII Corps troops at 10 a.m. finally drove the Rebels out of the West Woods. The fighting then shifted toward the Union center, principally along the sunken farm road— soon to be known to history as “Bloody Lane”— to which French had diverted his troops. Israel Richardson’s division deployed there as well once it crossed Antietam Creek.
Chris Howland is a senior editor for America’s Civil War.
Originally published in the September 2013 issue of America’s Civil War. To subscribe, click here.