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The Battle of Antietam

The battle of Antietam was fought around Sharpsburg, Maryland and took place on September 17, 1862. It was the bloodiest day in American history, with D-day being only half as bad. It was certainly the bloodiest day of the Civil War.

The Confederates entered the North with high spirits from their 2nd Bull Run victory. Lee was trying to invade the North, change Maryland into a Confederate state, and stop the North from invading the South for a while. His main objective in the North was to destroy the federal rail center in Harrisburg, Pennsylvania. If this were successful it would disrupt the Union supply line. Lee also went North to try to get Maryland to secede and gain more recruits for his army. He split his army into groups: one part went with Generals James Longstreet and D.H. Hill to Hagerstown. The next part under the commands of Thomas (Stonewall) Jackson, Lafayette McLaws and John Walker were sent to capture Harpers Ferry. Jackson sent Jeb Stuart as a rear-guard to South Mountain to prevent the Union from attacking the main Confederate army as they moved into Maryland. The Confederates surrounded the northeast, northwest, and east of Harpers Ferry. General Jackson attacked Harpers Ferry from the northwest. General Lafayette McLaws surrounded Harpers Ferry by way of Maryland Heights in the northeast. General John Walker surrounded Harpers Ferry by Loudoun Heights in the east. These three groups went on to capture 11,000 Union prisoners, 13,000 small arms, and 73 cannons from the Federal arsenal at Harpers Ferry. They then eventually met back up with Lee at Sharpsburg. James Longstreet and D.H Hill, after realizing the overwhelming amount of Union forces defending the passes of South Mountain, also went to join up with Lee at Sharpsburg. This is how the entire Army of Northern Virginia arrived at Sharpsburg.

The Union army started out in Washington recovering from their losses after 2nd Bull Run. The Union army’s morale and support of George McClellan was very high as they marched toward where many of them would take their final breath. They followed the Confederates west roughly three days march behind them.

While the Union army was marching over an abandoned Confederate campsite, a private found three cigars made by a Confederate staff officer. On the paper surrounding the cigars was written the special orders 191 written by Lee explaining to all of the Confederate generals what his moves were going to be before the battle. Apparently, accidentally two copies of the order were given to one of the Confederate generals. That general’s staff officer, for unknown reasons got hold of the extra copy, thought it was just ordinary paper and used it as a cigar wrapper. Once McClellan got hold of these orders he said, “here is a paper with which if I cannot whip Bobbie Lee, I will be willing to go home.”

It was possible for the battle of Antietam to start one or two days before it actually did if McClellan hadn’t thought that The Army of Northern Virginia (Confederate army) was so big and the Union army needed to prepare more. In fact, at that point, the Confederate force that was first to arrive at Sharpsburg was a small army of 18,000, and The Army of the Potomac (Union army) was a great army of 90,000. If McClellan had attacked earlier, the outcome of Antietam could have been a great Union victory. McClellan didn’t attack, so when the actual battle did start The Army of the Potomac engaged 75,316 men (McClellan saved some for reserves) and The Army of Northern Virginia engaged 51,844 men because McClellan had given the Confederates time to regroup at Sharpsburg.

There was some initial skirmishing near Antietam Creek just outside of Sharpsburg, between the two armies on September 16, the day before the battle. It happened just north of the fighting that would occur the next day in the cornfield in the northern part of the battlefield.

McClellan’s battle plan for the fight was to have the left and right flanks of his army attack the sides of The Army of Northern Virginia. Then when one of the sides broke through, the middle of his army would attack and have the side that broke through turn and attack the back of the center of the Confederates. The actual thing that happened was that the right of the Union line attacked first at six in the morning and the left of the Union line started at 1 in the afternoon, far after the time they were commanded to begin. The reason for this is not known but it disrupted McClellan’s battle plan.

Morning Phase (6:00 a.m. to 9:30 a.m.)

The real battle at Antietam Creek Maryland started on September 17, 1863 when the fighting in the cornfield near the German Baptist Church commonly called Dunkers broke out. Joseph Hooker was the Northern general in this part of the battlefield. Hooker had crossed Antietam Creek with his men to face the Confederate’s left line commanded by Thomas Jackson. The battle started in the North Woods, the most northern place on the battlefield that day. The Confederates eventually fell back to a cornfield directly south of the North Woods. The fighting in this cornfield was extremely bloody, and control of the cornfield changed hands almost fifteen times in three hours. Hooker later said, “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. It was never my fortune to witness a more bloody, dismal battlefield.” Eventually after much fighting Union General Sedgwick decided to make a charge against the Confederate line through the cornfield. He, however, charged right into a trap that Jackson had made. The trap was a crossfire; Jackson arranged his men into a C shaped line. Sedgwick’s men charged right into the middle of this C. It was a heartbreaking loss for the Union. The Confederate crossfire, in just half an hour, cost the Union almost 2,200 men. After all of this McClellan decided that he could not take the Confederate left and the next fighting to begin was in the center.

Mid-day Phase (9:30 a.m. to 1 p.m.)

The Confederates in the center of the battlefield, commanded by General D.H. Hill, were in a natural sunken road that they were to hold at all costs. Colonel John B. Gordon said to Lee “these men are going to stay here, general, till the sun goes down or victory is won.” They fired from this sunken road at the on-coming Northern generals French and Richardson’s men of General Sumner’s corp. Five times the Union line retreated but each time they came back. For some unknown reason the right of the Confederate line eventually faltered and collapsed. Union General Richardson took advantage of this opportunity and entered the Confederate right. He charged through the sunken road killing everybody in his path forming a Union crossfire. The Union broke through the middle of the Confederate line but McClellan was too cautious even though he had massed artillery and infantry organized to attack. Desperately Lee finally sent his last reserves under General Anderson to drive back the Union men from the center of the Confederate line. If McClellan had been more aggressive, he would have cracked the Confederate army in half. Just in his nature like he had done numerous times before, he became defensive and halted his advance thus ending the fighting at the place now called Bloody Lane. At this point heavy fighting began at the Lower Bridge over Antietam Creek at the southern part of the battlefield.

Afternoon Phase (1p.m. to 5:30 p.m.)

The Union general at this part of the battlefield was General Ambrose Burnside, and the Confederate general was Robert Toombs. The confederates were greatly outnumbered in the southern part of the battlefield but they had a very good strategic vantage point, high on a hill overlooking the Lower Bridge (later to be known as Burnside Bridge.) About 400 Georgians with only about two cannons opposed the Union forces. Burnside was supposed to have attacked in the morning, and after several urgent messages from McClellan ordering him to attack he eventually did at about 1o’clock in the afternoon. When he did attack he order massed infantry onto the Lower Bridge. The Confederates, however, had no trouble sniping the Union men off the bridge. Because of his hurried arrival Burnside did not have time to check the water level of the creek. In fact, it was possible to ford the creek in certain spots where the Union soldiers could have waded across instead of attacking over the bridge. Attack after attack on the bridge lost 500 Union men alone. Finally when Union forces started to scout upstream and downstream they found two places where they could ford (one upstream and one downstream.) After they had forded artillery and infantry over to the Confederate side of Antietam Creek, the Union pounded the flanks of the Georgians enabling successful charges across the Lower Bridge. Burnside’s men then pushed the Georgians back towards Sharpsburg. Burnside’s own men, however, were too slow in their advance. This let A.P. Hill’s Confederate corps arriving late from Harpers Ferry to join the fight. They were cleaning up the Union surrender of Harpers Ferry and most of the Confederates came in Union uniforms captured from the arsenal. This fooled Burnside’s men at Antietam long enough for Hill’s corps to drive them back to the Lower Bridge.

After the Battle

After the battle there was almost no change in the Union or Confederate’s line because McClellan was too cautious to capitalize on any of the possible three advancements at the Cornfields in the north, the Sunken Road in the middle, and the Lower Bridge in the south. The result was the enormous amount of casualties at Antietam (12,410 Union, 10,700 Confederates). This included 18 generals, 9 Union and 9 Confederates. Lee lost almost one-quarter of his army. The other result was that after many attempts to make McClellan move, Lincoln fired McClellan. There was no real decisive victory for either side. McClellan had planned to attack again but as usual he was too cautious and let the Confederates retreat the next night to Northern Virginia. Lee’s army retreated back south without achieving either of his goals, to bring Maryland into the Confederacy and to invade the North successfully. Lincoln saw this as a positive and considered this as a win coming off the Union’s previous humiliating losses. He saw this as a perfect time to present his Emancipation Proclamation to the United States freeing all slaves in the Confederacy.