Battle of Antietam; Preliminary Emancipation Proclamation Announced: September 1862

September 1862 in the Civil War

Confederate armies were on the move in Virginia and Kentucky as September 1862 began.  Major General John Pope’s Union Army of Virginia was in the process of slowly withdrawing to the Washington DC defenses following the defeat at Second Bull Run when it was attacked by Thomas “Stonewall” Jackson’s Corps on September 1st at Chantilly, Virginia.  Jackson was attempting to cut off the Army of Virginia’s retreat, but after fierce fighting that resulted in the deaths of Union generals Philip Kearny and Isaac Stevens, the Confederate attack was stopped. The Federals continued to withdraw and General Robert E. Lee’s Army of Northern Virginia prepared to invade Maryland.

John Pope had proven to be yet another ineffective Union commander in Virginia.  His army was folded into Major General George McClellan’s Army of the Potomac, and despite having reservations, President Abraham
Lincoln returned McClellan to full command of the newly merged army. Pope was assigned to Minnesota to deal with a Sioux uprising in that state.

Lee’s army moved to the Leesburg, Virginia area west of Washington and began crossing the Potomac into Maryland on September 4th, and occupied Frederick, Maryland on the 6th. On the 9th, Lee issued his Special Orders No. 191, which divided his army and sent Jackson to capture the large Federal garrison at Harper’s Ferry and the rest of the army to South Mountain and Hagerstown, Maryland.

McClellan cautiously moved his army northward.  On September 13th, two soldiers with the 27th Indiana Infantry found a copy of Lee’s Special Orders No. 191 wrapped around three cigars lying in a field near Frederick. With this information, McClellan could attack and defeat Lee’s army in detail if he could attack the separated parts before they could reunite, but the ever cautious McClellan waited 18 hours before putting his army in motion.

McClellan advanced toward South Mountain where Lee’s forces tried unsuccessfully to stop the Federals at three mountain passes in the Battle of South Mountain on September 14th. Although they failed to stop McClellan, the Confederates did delay the Union advance. Meanwhile, Jackson was at Harper’s Ferry and sent word to Lee that he expected to take the garrison on the 15th.  Lee decided to concentrate his army at Sharpsburg, Maryland, a few miles across the Potomac from Harper’s Ferry, and prepare to fight.

The Army of the Potomac began arriving late on the 15th and on into the 16th.  Jackson did indeed capture Harper’s Ferry on the 15th and hurried to Sharpsburg, leaving General A.P. Hill’s division behind to process the over 12,000 Union prisoners taken in the action.

Early on September 17th, the Battle of Antietam opened when Major General Joseph Hooker’s 1st Corps attacked the Confederate left, fighting back and forth across a cornfield. That was followed by an attack by the 12th Corps, followed by the 2nd Corps. The attacks and counterattacks resulted in thousands of casualties on both sides and the capture of a small amount of ground by the Federals before the two exhausted sides ended their fighting after five hours.

At midday, Union forces attacked the Rebel center, where the Confederates had established a strong defensive line in a sunken farm road. Multiple costly Federal attacks were launched against the position and both sides poured reinforcements into the fight before the Union troops finally forced the Confederates out. Although the Union 6th Corps was prepared to go forward and attack the now broken Confederate center, the ever cautious McClellan decided not to attack and ordered his commanders there to hold their positions.

On the Confederate right, 400 Georgia riflemen had the task of defending the Rohrbach Bridge crossing over Antietam Creek. The Georgians were in a very good defensive position on the high bluff that overlooks the bridge.  They held off Major General Ambrose Burnsides’ 9th Corps for three hours before the Federals successfully got a couple of regiments across and forced the Rebels out. Burnside took about two hours to get his men across the bridge (now popularly known as the Burnside Bridge)  and organized for an attack. He finally advanced toward Sharpsburg but was met by A.P. Hill’s Corps, arriving just in time from Harper’s Ferry. Burnsides’ attack was stopped, and the Battle of Antietam was over.

With nearly 23,000 total casualties on both sides, including approximately 3650 killed, the Battle of Antietam was the bloodiest one day battle of the Civil War.  McClellan did not renew the attack the next day, despite having a numerical superiority to the Confederates and thousands of relatively fresh troops who had seen little action on September 17th. Instead, Lee withdrew from Sharpsburg on the night of September 18thand 19th, and was soon safely back across the Potomac River in Virginia, ending the invasion. McClellan did not attempt to pursue and destroy the battered Confederate army on the 18th or any other time, much to the chagrin of Lincoln.

With Lee’s withdrawal from Maryland, the battle became the Union victory Lincoln had been waiting for since July, when he first proposed the Emancipation Proclamation to his cabinet. On September 22nd, Lincoln announced that as of January 1st, 1863, “all persons held as slaves, within any state, or designated part of a state, the people whereof shall then be in rebellion against the United States shall be then, thenceforward, and forever free.”  The Proclamation began the process of the ending of slavery in the country by declaring that slaves in any of the seceded states not under Federal control would be freed unless those states quit the war and rejoined the union.  (Slavery  would not be completely ended legally until the 13th Amendment to the Constitution went into effect in December 1865). The Proclamation  also made the objective of the war two fold:  to preserve the Union and to end slavery.  Freed slaves could also be enlisted in the U.S. Army and Navy, which was a  huge boost in manpower for the Union.

While much of the focus was on Lee’s invasion of Maryland, two Confederate armies under Generals Braxton Bragg and Edmund Kirby Smith were advancing from Tennessee into Kentucky. Bragg captured the 4000 man Federal garrison at Munfordville, Kentucky on September 17th. Union General Don Carlos Buell and his Army of the Ohio marched north from Tennessee to deal with the invasion. Buell arrived at Louisville on September 25th.

In Mississippi, General Sterling Price was ordered to march his army from Tupelo, Mississippi toward Nashville to prevent two Union divisions under Major General William Rosecrans from reinforcing Buell  in Kentucky.  Rosecrans left Corinth, Mississippi, and attacked Price at Iuka, Mississippi on September 19th. The fighting ended in a stalemate, but with additional Union forces approaching, Price withdrew from the field. Union casualties totaled about 800, while the Confederates had over 1500.

Rosecrans had stopped Price’s advance,  but his army escaped intact. Price joined forces with General Earl van Dorn, and would engage Rosecrans again in October.