For a couple of days after fighting on South Mountain in Maryland in September 1862, skirmishes and artillery fire punctuated the efforts of Robert E. Lee and George McClellan to regroup their armies.
Lee turned his attention to his original plan to invade Pennsylvania, and waited at the village of Sharpsburg, Md., for Thomas “Stonewall” Jackson to mop up the Federals at Harpers Ferry, Va., and join him. McClellan had assumed Lee would retreat across the Potomac River to the relative safety of Confederate Virginia. But he didn’t.
McClellan massed his own troops, cutting off Lee’s route to Pennsylvania along the Hagerstown Pike. Lee resolved to make a stand anyway.
Beginning at dawn September 17, the two armies surged back and forth across cornfields, through the woods, around a small country church and over a stone bridge crossing Antietam Creek.
By dusk, the once pastoral countryside surrounding the village of Sharpsburg—population about 1,300—had morphed into an apocalyptic tableau of incomprehensible carnage.
Lee braced for a rematch September 18, but McClellan characteristically hesitated, and on September 19, Lee escaped across the Potomac, his plans to invade Pennsylvania abandoned. At least for now.
The Battle of Antietam, however, had a host of repercussions— both on and off the field.
Whose side are you on?
In Sharpsburg, the response was mixed. Although western Maryland contained more Union loyalists than the state’s central and southern regions, divisions remained. Slaves had been sold on Sharpsburg’s town square, and many locals sympathized with the South. Reflecting these divisions, Maryland’s battle monument is the only one on the battlefield to be dedicated to both sides.
The Battle of Antietam occurred exactly 75 years after delegates to the Constitutional Convention in Philadelphia signed off on the U.S. Constitution.
A Confederate shot struck a stone outcropping in front of the 107th Pennsylvania’s position, bouncing over their heads. But at the Roulette Farm, the 102nd was plagued by swarms of angry bees.
On the same day as Antietam, British Foreign Secretary Lord John Russell agreed in a letter to Prime Minister Viscount Palmerston that if the Union suffered another defeat, Britain should join France in a proposal to mediate the American conflict, presuming the nation would be permanently divided. And if the North refused, “we ought ourselves to recognise the Southern States as an independent State.” But after Lee was stopped at Antietam, the British government had second thoughts. The release of Lincoln’s preliminary Emancipation Proclamation ignited support for the Union in abolitionist Britain, and the position of those who still wanted to intervene eventually became untenable. French Emperor Napoleon III, who was trying to take over Mexico, still wanted to step in—but ultimately declined to interfere without Britain.
Lee was looking beyond his next military engagement to the Union’s upcoming midterm elections when he plotted his Northern invasion. “The present position of affairs, in my opinion, places it in the power of the government of the Confederate States to propose…the recognition of our independence” to the United States, he wrote Confederate President Jefferson Davis on September 8. “The rejection of this offer would prove to the country that the responsibility of the continuance of the war does not rest upon us, but that the party in power in the United States elect to prosecute it for purposes of their own. The proposal of peace would enable the people of the United States to determine at their coming elections whether they will support those who favor a prolongation of the war, or those who wish to bring it to a termination.”
In other words, a Confederate victory on Northern soil might scare voters into electing to Congress a majority of Peace Democrats who were willing to let the South go, forcing Abraham Lincoln and the Republicans to accept a negotiated peace and recognize the Confederacy.
The loss at Antietam changed the game.
While Lee was burrowing into Maryland, Abraham Lincoln had made a pact with the Almighty, Naval Secretary Gideon Welles recalled. Five days after Antietam, Lincoln revealed to his Cabinet that he had “made a vow, a covenant, that if God gave us the victory in the approaching battle, he would consider it an indication of Divine will, and that it was his duty to move forward with the cause of emancipation,” Welles remembered. Lincoln had heeded the Cabinet’s advice in July to hold his Emancipation Proclamation until he could issue it on the strength of a Union victory. Although “the action of the army against the rebels has not been quite what I should have best liked,” Lincoln said, he made good on his promise to his Maker and rescued the proclamation from his desk drawer, where it had been stored all summer. As of January 1, 1863, slaves residing in states in rebellion would be “henceforth and forever free.”
While some have argued the proclamation didn’t actually free anyone since the states in rebellion did not recognize Lincoln’s authority, Lincoln saw it as a war powers tool—in areas of the South occupied by Federal troops, slaves could indeed claim freedom, thereby depriving Southern interests of their labor force. “Every slave withdrawn from the enemy is the equivalent of a white man put hors de combat,” General in Chief Henry Halleck wrote Brig. Gen. Ulysses S. Grant.
Suddenly the war wasn’t just about restoring the Union. Emancipation, always bubbling under the surface, now was an irrevocable factor.
Originally published in the September 2012 issue of America’s Civil War. To subscribe, click here.