After his victory over General John Pope at the Second Battle of Manassas, Robert E. Lee decided that it was time to invade the North. It was possible that Maryland, a border state, might still join the Confederacy, and Lee wanted to march his men through that state to try to impress it. Lee also wanted to take the war away from war-torn Virginia. Accordingly, at the beginning of September, he began to move his men into Maryland.
In the meantime, Lincoln had switched army commanders once more. The combined army was once again placed into the hands of George McClellan, the man who had been defeated by Lee in the Seven Days Battles. McClellan had the luck to find a copy of Lee’s Special Orders No. 191, which contained information about Confederate battle plans and dispositions. He followed Lee, and by September 15, 1862, both armies were positioned on opposite sides of Antietam Creek. McClellan waited until the 17th before attacking Lee, however. This was a grave mistake as on the 16th, most of Stonewall Jackson’s corps arrived after capturing Harpers Ferry.
On the morning of September 17, 1862, the Confederate army was entrenched on a series of slight rises west of Antietam creek. They held the town of Sharpsburg, and so the battle is alternately called the Battle of Sharpsburg. McClellan’s army was positioned east of the creek. That morning, he sent Joseph Hooker’s I Corps in an attack on the Confederate left flank north of the town. At dawn, Hooker’s artillery fired on the Confederates.
Confederates of Jackson’s II Corps, Lawton’s division, were lying in wait in Miller’s cornfield. Hooker remarked that “every stalk of corn in the northern and greater part of the field was cut as closely as could have been done with a knife, and the slain lay in rows precisely as they had stood in their ranks a few moments before.” They were initially driven back under the heavy onslaught, were reinforced and counterattacked. Another Union corps (XII, Mansfield’s) was sent in, which fought against Hood’s division near Dunker Church. In this fighting, the 1st Texas Regiment of the Texas Brigade suffered 83 % casualties. To support Mansfield, another Union corps was thrown in, Sumner’s II corps. These troops veered into the West Woods, where they were hit with heavy fire on both flanks, and are driven off.
More of Sumner’s men, French’s division and Richardson’s division, veered south into the sunken road Confederate position commanded by D. H. Hill. From mid-morning to 1 P. M. the fighting raged here. This road gained the name “Bloody Lane” after the fierce fighting here. The Federals made small breaches here, but could not exploit them. After 1 P.M., both sides were too exhausted to fight on.
Also around mid-morning, Ambrose Burnside began to assault the bridge southeast of town. They were repeatedly driven back by Georgian sharpshooters with heavy casualties. They finally crossed at about 1 P.M. After crossing, superior Federal numbers began to drive the Rebels back towards the town of Sharpsburg. Only the timely arrival of A.P. Hill’s division from Harpers Ferry saved the Confederate lines. Because some of Hill’s men wore blue uniforms, the Federals thought at first that Hill’s men were Union soldiers. Then, Hill launched a counterattack that drove Burnsides weary men back to the bridge they had captured earlier.
This bridge was named “Burnside Bridge” because of Burnsides repeated assaults. Sadly, Burnside had never bothered to check for fords near the bridge. If he had marched a half-hour to the south, he would have found a lightly guarded ford that he could have crossed unopposed and crushed the Confederates. Instead, his men were butchered trying to cross the narrow span. However, Lincoln seemed not to know about this as he appointed Burnside Army Commander after saying that McClellan had “the slows.”
To show that he had not lost, Lee stayed behind at Sharpsburg one more day before withdrawing. Antietam was the single most bloody day in the Civil War. Out of Lee’s desertion-riddled 45,000 man army, 13,000 were casualties. At the end of the day, Lee had zero reserves left to stop any break. McClellan’s army of 70,000 wasn’t even fully engaged. His army suffered 12,000 casualties. Because of the stoppage of the Confederate invasion, Maryland never did join the Confederacy. England and France turned their heads away from it, and Lincoln was free to issue his Emancipation Proclamation. The Confederacy had never been so near victory that autumn day in Maryland.