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This Day in History: The Battle of Antietam & the Emancipation Proclamation

On this day in 1862, Confederate General Robert E. Lee decides to make a stand! His decision would lead to the bloody Battle of Antietam.

Federal forces were then reeling from their defeat at the Second Battle of Bull Run. That battle had left Union General John Pope’s army retreating toward Washington, D.C. Abraham Lincoln soon merged Pope’s army into General George McClellan’s Army of the Potomac.

The Battle of Antietam, by Kurz & Allison

“[D]estroy the rebel army,” Lincoln ordered McClellan.

In the meantime, Lee had decided to invade Maryland. He divided his men, sending some towards Hagerstown and some towards Harper’s Ferry. His directive was written down in Special Order 191—which turned out to be a big problem!

Would you believe that some hapless Confederate soldier used a copy of Order 191 to wrap his cigars? And he dropped those cigars in a field where they were found by two Union soldiers! McClellan was ecstatic, reportedly remarking: “Here is a paper with which if I cannot whip ‘Bobbie Lee,’ I will be willing to go home.”

Hmm. Perhaps it wasn’t quite that easy. A Confederate sympathizer overheard the conversation and got word to Lee that his plans had been discovered.

Fortunately for Lee, the notoriously cautious General McClellan took 18 hours to get his troops moving once he learned of Lee’s order. Lee took the opportunity to block some mountain passes that McClellan would need. On September 14, a battle waged for control of these passes. The battle didn’t go too well for the Confederates, but it did at least delay McClellan’s movements a bit.

McClellan finally made his move on the morning of September 17. Union forces snuck through a cornfield and attacked Lee’s men. The battle quickly became intense. One participant, historian Paul Boyer writes, remembered that the cornfield “was so full of bodies that a man could have walked through it without stepping on the ground.”

A second phase of the fighting occurred on a road that would later become known as Bloody Lane. Confederates became trapped in a low-lying portion of the road. Thousands were killed or wounded.

As if that weren’t enough, a final phase of the battle occurred at Antietam Creek. The Union forces eventually outlasted the Confederates simply because of their overwhelming numbers. They might even have won, except Confederate reinforcements from Harper’s Ferry arrived on the scene at just the right moment. As night fell, the battle was effectively at a stalemate.

The casualties were staggering. According to historian James M. McPherson, the casualties during that single day at Antietam were twice the casualties of the War of 1812, the Mexican War, and the Spanish-American war COMBINED.

Perhaps unsurprisingly, then, Lee retreated back over the Potomac the next day, leaving Union forces in possession of the field. It was a costly (and bare) Union victory, but one that Abraham Lincoln was determined to utilize. Five days later, he issued a proclamation. The Confederate states had until January 1, 1863, to return to the Union. If they did, they could keep their slaves. Any state that refused would be subject to Lincoln’s planned Emancipation Proclamation.

Not one state returned to the fold. Instead, Lincoln would issue his Emancipation Proclamation, a document that freed slaves in the Confederate states, but not the northern states. (Yes, there were some.)

What if the Confederate states had taken Lincoln up on his offer? Would we still say that the Civil War was fought over the issue of slavery?

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