The second in a three-part series on the 150th commemorative anniversary of the Battle of Antietam.
The discovery by Federal soldiers of Robert E. Lee’s primary directive of troop movements would have been a calamity had it been discovered by soldiers under the command of anyone other than George McClellan. However, McClellan, typically, was lethargic and cautious, giving Lee sufficient time to avoid the disaster that would ordinarily have been the result of such error.
At South Mountain on September 14, McClellan was able to deliver a blow that would force Lee to stand at Sharpsburg rather than continue his northward operation. This was by no means the final punch McClellan could have struck, had he acted with greater haste.
As the battle developed from early on the morning of September 17, Antietam rapidly turned into a large-scale horror, eventually claiming the lives of more than 3,600 men from both sides, with the count of wounded and missing totaling another 19,000 men.
The generals McClellan had in place to halt Lee’s progress formed a roll call of the most recognizable leaders in the Army of the Potomac. Early in the day, large commands under Major Generals Joseph Hooker (above), Joseph Mansfield, and John Sedgwick (right) swept in from the north and east. Mansfield would be killed by Confederate fire before the morning was over; Sedgwick would also be taken down by a Confederate bullet, but not until spring of 1864.
It was a long, bloody, and difficult day; there had been many such days in the war, but this one was particularly savage. Per Civil War scholar Bruce Catton:
Tactically, the battle was a draw. The Federals attacked savagely all day long, forcing the Confederates to give ground but never quite compelling the army to retreat, and when Lee’s battered army held its position next day, McClellan did not renew the attack. But on the night of September 18 Lee took his worn-out army back to Virginia. Strategically, the battle had been a Northern victory of surpassing importance. The Southern campaign of invasion had failed. The Federals had regained the initiative. Europe’s statesmen, watching, relaxed: the time to extend recognition had not arrived, after all.
One year and five months after the war’s beginning at Fort Sumter, with thousands of lives taken, the nation remained divided and at a draw. Each side, however, had a few cards to play before it folded. Robert E. Lee had one more trip north in his future, while Abraham Lincoln, more immediately, planned to issue a proclamation that would have more impact on the future of America than any document since the Declaration of Independence.
—Warren Perry, Catalog of American Portraits, National Portrait Gallery
Joseph Hooker, / Mathew Brady Studio / Albumen silver print, c. 1863 / National Portrait Gallery, Smithsonian Institution
John Sedgwick / Mathew Brady Studio / Wet-collodion negative, 1862 / National Portrait Gallery, Smithsonian Institution; Frederick Hill Meserve Collection
Bruce Catton, The Civil War (New York: Houghton Mifflin, 1960).