Despite advice from his corps commanders to withdraw during the night of the 17th, Lee said Mc Clellan would not attack the next day and remained in place until withdrawing on the night of the 18th.
Such Union pursuit as there was ended in a sharp skirmish just south of the Potomac at Shepherdstown, in what is now West Virginia.
Fought primarily on September 17, 1862, between the town of Sharpsburg, Maryland, and Antietam Creek, it ended Gen. Union: 12,400 Confederate: 10,300 View Details of Antietam Casualties Antietam Images, Pictures and Photos See our Battle Of Antietam Pictures View our Antietam Battlefield Maps Explore articles from the History Net archives about the Battle Of Antietam » See all Antietam Articles Shortly after routing the Union Army of Virginia under Maj. John Pope in the Second Battle of Bull Run (Second Battle of Manassas) in August, 1862, Lee led his own Army of Northern Virginia across the Potomac into Maryland.
Reasons for this invasion included taking pressure off the Shenandoah Valley—"The Breadbasket of the Confederacy"—at harvest time; encouraging European support for the Confederacy by winning a battle on Northern soil; and demoralizing Northerners to reduce their support for the war while encouraging the slave-holding state of Maryland to secede and join the Confederacy.
Instead, fearing Lee might outnumber him, he moved his men to the ridges east of Antietam Creek, where he paused to let them rest. "Jeb" Stuart’s cavalry guarding the gap between the Potomac and the infantry’s left flank.
Battle of Sharpsburg, resulted in not only the bloodiest day of the American Civil War, but the bloodiest single day in all of American history. Sharpsburg, Washington County, Maryland September 17, 1862 Union: Major General George B. Lee Union Army: 75,300 Confederate Army: 52,000 South Mountain Miller’s Cornfield Dunker Church East Woods West Woods Bloody Lane (aka Sunken Road) Burnside Bridge (Rohrbach Bridge) Union victory, in that Lee withdrew to Virginia.The benefits of the intelligence windfall that dropped into Mc Clellan’s hands were blunted, however, because a Southern sympathizer informed Lee that Mc Clellan had a copy of his orders, and because Mc Clellan moved with his typical glacial pace.He allowed 17 hours to pass before marching toward Lee’s force, allowing time for the Confederates to begin regrouping around the town of Sharpsburg at the base of South Mountain.Believing the routed Union army would require time to rebuild, Lee took the bold step of dividing his own army, sending portions of it to capture various objectives.Primarily, these objectives involved using part of Lieutenant General Thomas "Stonewall" Jackson’s corps to capture the Union garrison at Harpers Ferry, Virginia (now West Virginia), while the largest corps, that of Lt. James Longstreet, proceeded on the road toward Sharpsburg. Mc Clellan, who had been recalled from the Virginia peninsula along with the Army of the Potomac (see Seven Days Battle).
Rocky outcroppings throughout the battlefield caused solid-shot shells to ricochet wildly. The oldest general officer in Mc Clellan’s army, the 59-year-old Mansfield was mortally wounded while riding forward to reconnoiter and was replaced by Brig. Reinforcements that might have carried the day for the Union at that point never arrived, and another Federal drive stalled. French’s division swung to the left, toward the center of the Confederate line. A sheet of flame erupted from the sunken road and the crest of the ridge was covered with a blue blanket of dead or wounded Union soldiers.