August 28–30, 1862 – The Confederate Army under the command of Major General Robert E. Lee fought and won a major victory at the Battle of Second Manassass.
August 31, 1862 – Confederate Major General Robert E. Lee decided to send Major General Thomas (Stonewall) Jackson’s wing to Chantilly, Virginia in an effort to cut off Union Major General John Pope’s Army of Virginia from retreating to Washington.
September 1, 1862 – The Battle of Chantilly occurs. Confederate Major General Thomas Jackson fails to get his wing between Pope’s Army and Washington. Confederate Major General James Longstreet’s wing arrives that evening to reinforce Jackson. Remains of the Union Army of Virginia retreated to Washington.
September 2, 1862 – Union cavalry engaged a superior Confederate cavalry force at Leesburg. They managed to push back the Confederate cavalry at a severe cost, and then fell back into Harper’s Ferry. This cleared the way for the Confederate Army to march toward the Potomac River.
Union President Abraham Lincoln named Major General George McClellan to command the fortifications surrounding Washington. This made McClellan in command of his Army of the Potomac once more.
September 3, 1862 – While encamped at Centreville, General Lee wrote to Confederate President Jefferson Davis that he had decided to cross into Maryland. General Lee than began moving his army north toward Leesburg, Virginia. This is the starting point of the Maryland Campaign.
September 4, 1862 – Elements of the Army of Northern Virginia crossed into Maryland from Loudoun County near Point of Rocks.
September 5, 1862 – Union General McClellan and his newly reorganized Army of the Potomac began it’s pursuit of the invading Confederate Army. McClellan marched his army toward Maryland with six corps, while leaving two corps behind to defend Washington.
Brigade of Confederate Cavalry under the command of Brigadier General Fitz Lee crosses the Potomac and skirmishes with elements of Union Major General Alfred Pleasanton.
September 5-6, 1862 – Major General Robert E. Lee and the main body of the Army of Northern Virginia crossed the Potomac River at White’s Ford.
September 7, 1862 – The main portion of the Confederate Army advanced into Frederick, Maryland which was the concentration point of the Army of Northern Virginia.
Brigadier General John Walker crosses the Potomac River near the Monocacy Aqueduct.
September 9, 1862 – Lee’s Confederate Army is fully concentrated at Frederick, Maryland. Frederick is not as pro-southern as Lee was promised. General Lee issues Special Order No. 191. Union General McClellan’s Army of the Potomac is between Frederick, Maryland and Washington. General John Walker reentered Virginia, in Loudoun County.
September 10, 1862 – Special Order No. 191 is carried out by Lee’s subordinates. Jackson’s command will resume its march to Martinsburg via Turner’s Gap and capture the Federal garrison there, then concentrating his wing on capturing the garrison at Harper’s Ferry. Longstreet’s wing was to march via Turner’s Gap to Boonsboro and halt, focusing on the supply train there. Generals Lafayette McLaws and Richard Anderson were to follow behind Longstreet and at Middletown take the direct road toward Harper’s Ferry and once there, lay siege on Maryland Heights. General John Walker was to lay siege on the Virginia side of Harper’s Ferry at Loudoun Heights. General Daniel Harvey Hill’s Division was guarding the rear of the Army of Northern Virginia at Turner’s Gap. General JEB Stuart ordered the detachment of several squadrons of his cavalry, sending portions of it with all commands of the Confederate Army. The body of cavalry is to bring up stragglers falling behind.
September 11, 1862 – Confederate General McLaws arrived at Brownsville, 6 miles northeast of Harpers Ferry. He left approximately 3,000 men near Brownsville Gap to protect his rear and moved 3,000 others toward the Potomac River to seal off any eastern escape route from Harpers Ferry. General Walker was ordered to destroy the aqueduct carrying the Chesapeake and Ohio Canal across the Monocacy River where it empties into the Potomac, but due to the difficulty in demolishing the stone structure, the attempt was abandoned.
During the morning hours portions of the 1st Virginia Cavalry of General Stuart’s Cavalry Division entered Hagerstown, Maryland. During the afternoon, the head of Toomb’s Brigade entered Hagerstown. (note Toomb’s was not present during the Maryland Campaign)
Jackson’s men advanced to the garrison at Martinsburg, not realizing it had been evacuated upon their approach. The troops of the Martinsburg garrison fell back to Harper’s Ferry. Jackson continues his march to Harper’s Ferry, losing one day due to the unoccupied Martinsburg garrison. The Union garrison at Winchester was also evacuated.
September 12, 1862 – McLaws dispatched the brigades of Brigadier Generals Joseph B. Kershaw and William Barksdale to seize Maryland Heights and skirmishes break out while Union troops defend the area. This officially begins the Siege of Harper’s Ferry.
September 13, 1862 – Confederate General John Walker reaches the base of Loudoun Heights. General Kershaw began his attack at about 6:30 am on Maryland Heights. By the afternoon Union forces on Maryland Heights retreat to Harper’s Ferry.
McClellan enters Frederick, Maryland and was received with much enthusiasm by the townspeople. Lee’s Special Order No. 191 dispatch was found near Frederick on the Best Farm. McClellan now had to develop a plan of attack to engage each individual section of Lee’s divided army.
Portions of McClellan’s Army skirmished with the rear of the Confederate cavalry in the streets of Frederick.
Captain Charles Russell of the 1st Maryland Cavalry and nine troopers slipped through the Confederate line to take a message to McClellan informing him that the besieged town could hold out for only a mere 48 hours.
Major General William Franklin’s Sixth Corps encamps at Jefferson, Maryland under orders to punch through Crampton’s Gap and relieve the garrison at Harper’s Ferry.
Skirmishes occur as Union Major General Alfred Pleasanton’s cavalry leaves Frederick in pursuit of Confederate cavalry. Skirmishes occur at Braddock’s Gap on the National Road, Middletown, and Quebec School House near Burkittsville. Pleasanton also sends portions of his cavalry northward to Emmitsburg, Maryland and Gettysburg, Pennsylvania for intelligence.
Portions of Stuart’s 9th Virginia Cavalry guard Hamburg Pass on the Catoctin Mountain overlooking Lewistown and modern day Thurmont, Maryland.
Major General Daniel Hill guards Turner’s Gap and sees portions of McClellan’s Army of the Potomac at Middletown.
Near Brownsville, Brigadier General Paul Semmes orders detachments of his brigade to guard Brownsville Pass in addition to sending a small brigade under Colonel John Parham to guard Crampton’s Gap.
General JEB Stuart leaves a portion of his cavalry under Colonel Thomas T. Munford and Chew’s Battery to guard Crampton’s Gap, while leaving a portion of the 5th Virginia Cavalry and a section of Stuart’s Horse Artillery under Captain John Pelham at Fox’s Gap.
September 14, 1862 – The 9th Virginia Cavalry fell back from Hamburg Pass through the town of Hamburg to Hamburg Gap on South Mountain. General Daniel Hill orders a regiment of infantry to Hamburg Gap for picket duty. Hearing the sounds of gun fire, the 9th Virginia Cavalry leaves Hamburg Gap, riding toward Boonsboro.
Early in the morning, the 9th Corps and the 1st Corps make their way toward South Mountain. The 9th Corps, at Bolivar files to the left to cross South Mountain at Fox’s Gap while the First Corps files off the right to cross South Mountain near Turner’s Gap via Frostown and Mount Tabor.
The Battle of South Mountain erupts at Fox’s Gap as a North Carolina brigade of Confederate infantry along with the 5th Virginia fight off the head of Major General Jesse Reno’s 9th Corps. After several hours of fighting, the battle at Fox’s Gap stalls until the afternoon, as reinforcements occupy Fox’s Gap arriving from Hagerstown. Late in the afternoon, the battle at Fox’s Gap ensues and by night, the Confederate soldiers’ barely hold Fox’s Gap.
One mile to the north at Turner’s Gap, a battle ensues as Union troops make their way from Bolivar to attack a small Confederate brigade guarding the mountain pass. Another mile northward near Mount Tabor and Frostown, the Union 1st Corps under the command of Major General Joseph Hooker attacked Confederate reinforcements in an effort to side step Turner’s Gap at Frostown Gap. The fighting comes to halt just after dark and the Confederate troops hold Turner’s Gap.
Seven miles to the south, Major General Franklin’s 6th Corps enters Burkittsville around mid morning. Skirmishing occurs during the early afternoon and a cannonade from Brownsville Gap ensues. Unable to do much damage from Brownsville Gap, General Semmes sends troops to reinforce those at Crampton’s Gap just as Franklin’s Corps launches a massive attack on the meager Confederate defenders; unfortunately Semmes realized he was guarding the wrong mountain gap. When reinforcements finally came to the aide of his Confederate comrades, it was too late. Franklin’s Corps secures Crampton’s Gap and settles in for the night, not marching to the relief of the garrison at Harper’s Ferry.
As darkness sets in, General Robert E. Lee, not realizing that McClellan was marching on the rear of his army, orders all troops at Fox’s Gap, Turner’s Gap and Frostown Gap to fall back toward Boonsboro. At this point, Lee thought that his Maryland Campaign was over and ordered all troops to Sharpsburg. Meanwhile Jackson was still at Harper’s Ferry and had not received its surrender.
In the middle of the night roughly 1,400 Union cavalry soldiers sneak out of Harper’s Ferry and capture a wagon supply train that belonged to General Longstreet’s command. The cavalry escort this wagon train to Chambersburg, Pennsylvania.
September 15, 1862 – General Jackson accepts the surrender of the garrison at Harper’s Ferry, where about 12,500 Union soldiers surrendered. Jackson sent a courier to Lee with the news of the surrender. Lee sends the courier back to Jackson stating to get his troops to Sharpsburg as fast as he could. With the surrender of the garrison Lee realized that the Maryland Campaign could still be carried out.
After the Battle of South Mountain, McClellan was in a position to destroy Lee’s army but did not follow up the pursuit until a day later on the 16th.
September 16, 1862 – In the evening near Sharpsburg, McClellan confronted Lee, who was defending the western portion of the Antietam Creek.
September 17, 1862 – At dawn the Battle of Antietam erupted. By days’ end, the battle was at a draw. Over 21,000 casualties in wounded, missing and worse killed in a period of one day, making this battle the most single bloodiest day of the American Civil War.
September 18, 1862 – Skirmishes occurred while Lee evacuated the wounded through Shepherdstown. No major assault would occur by either army.
September 19, 1862 – Lee pulls his army across the Potomac River to Shepherdstown. Before dusk, a small portion of the Fifth Corps attacked the rear of Lee’s army. After the severe engagement, the union attackers were recalled.
September 20, 1862 – Two Union Divisions made there across the Potomac River and were met by Major General A.P. Hill’s Division who had marched five miles back to Shepherdstown. The Union attackers were ordered to retire back to the Maryland shore ending the Battle of Shepherdstown. As for General Lee, he abandoned the Maryland Campaign. Learning from the mistakes of the Maryland Campaign in 1862, Lee would launch another invasion of the north, this time it would be in Pennsylvania.