Lee had been appraised of the military situation in Maryland on September 15, 1862. He therefore ordered generals Longstreet and Hill to take defensive positions at Sharpsburg, Maryland. Lee also ordered generals Jackson and McLaws to arrive to Sharpsburg as soon as possible. Lee was injured and using an ambulance to survey where the battle of Antietam would be fought.
General Robert E. Lee's lost orders No.191 fell into the hands of Union General George B. McClellan on September 13, 1862. That evening, a Confederate sympathizer became aware of this and alerted Lee. This was remarkable, and of value to Lee to know this.
General Robert E. Lee instructed General James Longstreet to seize the Maryland towns of Boonsboro and Hagerstown. Lee's goal was to use both towns as a base of operations in Maryland.
The main and immediate concern of General Robert E. Lee on September 14, 1862 was to prevent George B. McClellan from smashing through the division of D.H. Hill at Turner's Gap. This placed Confederate General James Longstreet's divisions to be unable to be concentrated for the defense of Boonsboro.
The battle was fought September 17th, 1862. It is also known as the Battle of Sharpsburg. It was the last battle of General Robert E. Lee's first campaign into the North, and was the bloodiest single day of the entire war.
General Robert E. Lee
In early September of 1862 Confederate General Robert E. Lee had two options when his army reached Leesburg, Virginia. From that town, Lee could move his forces against Union forces in the northern end of the Shenandoah Valley and Harper's Ferry, or cross the Potomac River to the west of Washington DC and invade Maryland. His decision was to invade Maryland. This was an eventful move as the month of September moved along.
On the 14th of September 1862, Confederate General Robert E. Lee had a major concern as the US Civil War Battle of Antietam was fast approaching. First on his list was to prevent General McClellan from breaking through and destroying General D. H. Hill's division at Turner's Gap and attacking the forces of General James Longstreet before Longstreet could make a defensive stand at Boonsboro.Should McClellan be successful, Lee would have no choice but to retreat to Virginia in order to save Longstreet's army.
On September 14, 1862, General George B. McClellan ordered General Franklin to advance his corps toward the town of Harper's Ferry as part of the Union's efforts during the Maryland Campaign. McClellan sought to secure the strategic location and cut off Confederate forces. Franklin's orders emphasized a swift movement to support the broader objectives of the Union Army in the area. This maneuver was crucial in the context of the approaching Battle of Antietam.
Robert E. Lee
Robert E. Lee.
Major General Irvin McDowell actually had two stints as commander of the Union Army. The first was from March 13, 1862 until April 4, 1862. The second was from June 26, 1862 _ September 5, 1862.
General Robert E. Lee planned and led the Army of Northern Virginia across the Potomac River and into Maryland. On September 17, 1862, his army the Union's Army of the Potomac would engage each other in the Battle of Antietam.