by Andy Mateja

The North called it the battle of Antietam and the South called it the battle of Sharpsburg. However both sides could not deny that it was the bloodiest single day battle in the entire Civil War. Like Gettysburg, this battle was entirely by accident, as General Robt E Lee had intended to move his forces into Pennsylvania and wage war on northern soil with the hopes of finally receiving foreign recognition of the new Confederate Government from England and France. Lee, fresh from brilliant victories outside of Richmond and Second Bull Run, had reversed the dynamics of the war in the East from imminent Confederate disaster to unchecked advancement into the heart of the heavily populated Northern states.
Lee gambled that by keeping the momentum going, it would keep the Union army and Washington leadership off guard and with a significant victory on Northern soil bolstered by thousands of Confederate volunteers from Maryland, the war would be over before the mid-term elections in November.
Lee however needed to make sure his lines of supply and communication were secure before advancing into Pennsylvania. The Federal garrison at Harpers Ferry was the obstacle that needed to be overcome.
Lee issued Special Order 191 which temporarily divided his forces to allow for six of his nine divisions under Stonewall Jackson to capture the garrison at Harpers Ferry and secure his lines of communication while one of the remaining three divisions blocked mountain passes against potential Union advances and the other two converged on Boonsboro, miles away. In essence, Lee had divided his army in multiple parts in hostile enemy territory with little chance of rapid concentration
Nine copies of Special Order 191 were written and delivered to each of Lee’s nine division commanders making sure each commander understood what is expected of him. However, a tenth copy of Special Order 191 was issued by General Stonewall Jackson which he sent to his subordinate Gen D.H.Hill. However Lee had already sent a copy of the special order to D.H. Hill so the second “copy” was not given any thought until a few days later what a Union soldier found a copy of Special Order 191 addressed to D.H. Hill, wrapped around three cigars. No one could say for certain if the copy found was the one issued by Lee or Jackson , although Hill swore the only copy he received was from Jackson.
When the copy of Lee’s Special Order 191 was turned over to McClellan, the normally cautious Union commander became elated and began to move aggressively toward Lee. He felt he had a golden moment to defeat Lee’s army piece meal and end the war. It appeared both sides now viewed this campaign as more than a simple “battle”.
When Lee learned that McClellan had secured a copy of his special order and was moving swiftly against him, he concentrated the elements of his army closest to him while awaiting Jackson, with the bulk of the army, to finish off the Union forces at Harpers Ferry. Lee’s point of concentration was Sharpsburg MD, on the Antietam Creek. Lee could only pray that Jackson would complete his task and return to the army before McClellan launched his anticipated attack.
Fortunately for Lee, McClellan continued to overestimate the size of his forces and cautiously fought his way through Turner’s and Crampton’s Gaps while giving Lee’s army additional time to concentrate. On September 15th the garrison at Harpers Ferry surrendered to Stonewall Jackson which included 11,500 troops and 73 cannon. Time was running out for McClellan to make an aggressive attack against Lee while his forces were still divided. Even though McClellan outnumbered Lee’s forces throughout this entire campaign, he allowed Lee to bluff hum again with a much smaller (and divided) force at Sharpsburg who defiantly dug in and prepared for McClellan’s attack. McClellan hesitated again and allowed a full day to pass before launching his attack. During that day, Stonewall Jackson returned with the bulk of his forces, more than doubling Lee’s forces awaiting McClellan’s attack. Had McClellan attacked Lee on September 15th or even the morning of the 16th, he would have faced 15,000 Confederate troops instead of the 42,000 he fought on the 17th. To top it off, McClellan assumed Lee’s force to be somewhere between 100,000-130,000 men which caused him to hold a large portion of his own force in reserve that he did not use at all during the battle.
The battle began early on the morning of September 17th at the Northern end of the Confederate line. Fierce fighting raged in the North, East and West Woods and the Cornfield North of the Dunker Church, Arriving during the late afternoon-evening of the 16th, Stonewall Jackson had placed the bulk of his troops in this vicinity. Hood’s division (now under Jackson) attacked at the Dunker Church and was fought to a frazzle, sustaining and inflicting heavy casualties.
After fighting the superior Union forces to a standstill, the battle slowly shifted to the center of the line where Longstreet’s men were concentrated. DH Hill’s division (now under Longstreet) dug in at the Sunken Road which was later to be known as Bloody Lane and again fought the vastly superior Union forces to a standstill. Meanwhile on the Southern end of the line, General Burnside pushed forward to cross the Rohrbach Bridge in an attempt to flank the Confederate forces. However effective sniper fire from 450-500 Georgians kept Burnside’s 12,000 man force at bay for most of the morning and early afternoon. Finally when a crossing of the Antietam creek was undertaken, Burnside was able to bypass the Confederate sharpshooters, cross the bridge (later called Burnside Bridge in his honor) and move toward Sharpsburg and flanking Lee’s entire army.
It looked like the end for Lee and his army who fought so bravely throughout the day as there were no fresh troops to stop Burnside. Lee had committed every available man to the conflict with none in reserve. However fate stepped in to save the day……………..
The last remaining Confederate division –AP Hill’s- was still at Harpers Ferry on the morning of the 17th dealing with issues of the Union surrender. Lee had sent AP Hill an order at 6:30AM to march quickly to Sharpsburg – 17 miles away – to aid in the defense against McClellan’s attack. A.P. Hill ordered a forced march which caused almost half of his division to fall out of line. He arrived on the field with 2000 men out of 3300. However his arrival is fortuitous for Lee’s army, as Hill was able to hit Burnside squarely in the flank and halt his turning movement against Lee. This effectively ended the battle of Antietam.
The was the costliest battle in American lives in history – then as well as now. Almost 23,000 soldiers were either killed wounded or missing in less than 15 hours of fighting. Lee fought with every man available to him and lost almost 25% of his effective strength. McClellan used only 75% of his available strength and lost approximately 24%.
Undeterred and severely weakened, Lee chose to dig in and await further attack on Sept 18th from McClellan. McClellan, with almost 22,000 fresh troops on hand, chose to play it safe and await Lee’s counterattack, which he was sure was coming from Lee’s “vastly superior” force. In essence, McClellan allowed his golden opportunity to destroy Lee’s army once and for all and end the Civil War to slip through his fingers. This and subsequent hesitations cost McClellan his command of Federal troops once and for all, while Lee, allowed to retreat and rebuild his army, continued to fight on and inflict heavy Union casualties for another 2 ½ years.
It was Lee’s first foray into Union territory……..and would not be his last.