Wednesday, September 3: General Robert E. Lee’s Army of Northern Virginia began moving to relieve Federal pressure on Virginia by invading the North. The troops moved west toward Leesburg and occupied Winchester. In Washington, Federal General John Pope conferred with President Abraham Lincoln and General-in-Chief Henry W. Halleck. Pope delivered a report accusing General Fitz John Porter of disobeying orders and General George McClellan of failing to support him in the Battle of Second Bull Run. In the Dakota Territory, Sioux Indians unsuccessfully attacked Fort Abercrombie as part of their uprising against Federal authority. In Kentucky, Confederates under General Edmund Kirby Smith continued their invasion by occupying the state capital of Frankfort.
Thursday, September 4: Lee’s Confederates began crossing the Potomac River into Maryland; the crossing continued for three days. Various skirmishes ensued as politicians conferred in Washington, Federals evacuated Frederick, Maryland, and McClellan began reorganizing the Army of the Potomac. In Minnesota, Federals skirmished with Sioux Indians at Hutchinson. In Kentucky, John Hunt Morgan’s Confederate raiders joined Edmund Kirby Smith’s men. In western Virginia, Confederates under General A.G. Jenkins crossed the Ohio River for a brief northern invasion.
Friday, September 5: In Washington, Halleck informed Pope that his Army of Virginia would be consolidated into McClellan’s Army of the Potomac. McClellan began gathering Federal troops around Washington as Robert E. Lee continued advancing on Frederick, Maryland. In Indiana, Governor Morton called on citizens to form militias along the Ohio River in defense of a potential Confederate invasion. At Sparta, Tennessee, Bragg proclaimed, “Alabama is redeemed. Tennesseans! your capital and State are almost restored without firing a gun. You return conquerors. Kentuckians! the first great blow has been struck for your freedom.” Meanwhile, General Don Carlos Buell’s Federals abandoned northern Alabama, falling back to Murfreesboro and Nashville.
Saturday, September 6: In Maryland, Confederates under General Thomas “Stonewall” Jackson occupied Frederick. Federal cavalry skirmished with the Confederate invaders over the next nine days. Robert E. Lee had expected to gain recruits in Maryland, but Frederick was abandoned and an observer wrote, “everything partook of a churchyard appearance.” In Virginia, Federals evacuated the important supply center at Aquia Creek near Fredericksburg. John Pope was assigned to command the new Department of the Northwest, which consisted of Wisconsin, Iowa, Minnesota, and the Nebraska and Dakota territories. His main task was to suppress the Sioux Indian uprising. In the Dakota Territory, the Sioux unsuccessfully attacked Fort Abercrombie a second time.
Sunday, September 7: George McClellan’s Army of the Potomac began slowly moving northward from Washington, protecting the capital and Baltimore while unaware of Robert E. Lee’s location. Harrisburg, Pennsylvania and Hagerstown, Maryland experienced “tremendous excitement,” with frantic people preparing for a Confederate invasion. The Federal arsenal at Harpers Ferry was isolated by Lee’s forces. President Lincoln worried about events in both the eastern and western theaters, asking “Where is Gen. Bragg” and “What about Harper’s Ferry?” U.S.S. Essex battled Port Hudson batteries on the Mississippi River. Confederate President Jefferson Davis wrote to Robert E. Lee, Braxton Bragg, and Edmund Kirby Smith that they should inform northerners “That the Confederate Government is waging the war solely for self-defence, that is has no design of conquest or any other purpose than to secure peace and the abandonment by the United States of its pretensions to govern a people who have never been their subjects and who prefer self-government to a Union with them.”
Monday, September 8: Apprehension intensified in Maryland and Pennsylvania, as Robert E. Lee’s Confederates continued advancing. Lee proclaimed to Maryland residents: “The people of the Confederate States have long watched with the deepest sympathy the wrongs and outrages that have been inflicted upon the citizens… We know no enemies among you, and will protect all, of every opinion. It is for you to decide your destiny freely and without constraint. This army will respect your choice, whatever it may be.” President Lincoln asked George McClellan at Rockville, Maryland, “How does it look now?” General Nathaniel Banks assumed command of the Washington defenses. Various skirmishing occurred in Tennessee and Kentucky.
Tuesday, September 9: At Frederick, Robert E. Lee issued Special Orders No. 191, calling for “Stonewall” Jackson to attack Harpers Ferry and General James Longstreet’s corps to advance on Boonesborough, Maryland. These orders would later be found by Federal troops and forwarded to George McClellan. General Samuel P. Heintzelman was given command of the Washington defenses south of the Potomac.
Source: The Civil War Day-by-Day by E.B. Long and Barbara Long (New York, NY: Da Capo Press, 1971)