Sumter surrendered. The reverberations of this shot were to shake the very foundations of the Nation. Gone was the period of apathy and indecision. Events now moved with lightning-like rapidity.

On April 15, Lincoln issued his call for 75,000 volunteers, and soon troops were pouring into Washington. On May 23, Virginia voted to ratify the Ordinance of Secession, and the next day columns of Federal troops crossed the Potomac and seized Alexandria and Arlington Heights. Eight days later Richmond became the capital of the Confederacy and the chief objective of the Federal armies in the East. Stretching from the Ohio to Chesapeake Bay, Virginia constituted the wealthiest and most populous state of the Confederacy. Here were to be found rich natural resources and a heavy network of railroads and highways for military transport. These military advantages, however, were somewhat offset by the deep waters which flanked much of the state, increasing its vulnerability to Federal attack.

Straight across the path of one of the main high roads to Richmond from the north lay Manassas, a small railroad settlement, only a few miles east of the Bull Run Mountains. Here the Orange and Alexandria Railroad formed a junction with the Manassas Gap line which extended westward through the Blue Ridge to Strasburg, near Winchester. By seizure of this significant junction, located approximately 25 miles southwest of Washington, the Federal army could follow the Orange and Alexandria southwest to Gordonsville and thence proceed by the Virginia Central eastward to Richmond. This, with good supporting highways, would assure an overland approach that would avoid many of the natural barriers found in the shortest route by Aquia Creek and Fredericksburg.

The significance of Manassas was likewise apparent to the Confederates. As early as May 6, Col. St. George Cocke, commanding the Potomac Department, had received a dispatch from Gen. Robert E. Lee: “You are desired to post at Manassas Gap Junction a force sufficient to defend that point against an attack likely to be made against it by troops from Washington.”

The first troops to arrive were two raw, undrilled, and ununiformed Irish regiments from Alexandria, armed with altered muskets. By May 14, Cocke was able to write Lee that he had succeeded in assembling a force of 918 men at Manassas. That he had a clear grasp of the military significance of the area is seen in his dispatch to Lee the next day: “It is obvious, sir, with a strong corps d’armee at Manassas, and at least a division at Winchester, these two bodies being connected by a continuous railway through Manassas Gap, there should be kept at all times upon that road ample means of transportation. These two columns—one at Manassas and one at Winchester—could readily co-operate and concentrate upon the one point or the other.” Here then was a significant germ of Confederate strategy.

As a phase of this strategy, Brig. Gen. Joseph E. Johnston had been sent to take command of the Confederate force of about 12,000 men stationed in the northern end of the Shenandoah Valley at Harper’s Ferry. Here was the gateway to the North through the Cumberland Valley of Maryland and here passed the great Baltimore and Ohio Railroad which connected Washington with the West. But Maj. Gen. Winfield Scott, then in command of the Army of the United States, had dispatched Maj. Gen. Robert Patterson with a force of about 18,000 men to seize this strategic position and to prevent, at all odds, the junction of Johnston’s forces with the Confederate army at Manassas.

Confederates Look to Manassas Defenses

On June 1, Brig. Gen. Pierre G. T. Beauregard, the Confederate hero of Fort Sumter, arrived to take command at Manassas. Two days later he was writing President Jefferson Davis requesting reinforcements. At this early date the defenses of Manassas appeared anything but formidable to the eyes of an English lieutenant of artillery who, arriving at night, viewed them for the first time: “I could scarcely believe that this was a great military depot, there being nothing within my range of vision to indicate that such was the fact. The station itself was a low, one-storied building, about seventy-five feet in length, with bales and boxes scattered about; a house of refreshment close by was uninviting, and except one or two small cottages scattered here and there, naught was to be seen.”

Brig. Gen. Pierre Gustave Toutant Beauregard in command of the Confederate Army of the Potomac. Courtesy National Archives.

By the end of June this picture had materially changed. The roads, the fields, and the town were filled with soldiers by the thousands. Around the junction massive fortifications had been erected running out in different directions from the station. Through the embrasures of these earthworks the muzzles of heavy cannon pointed menacingly toward Washington. Acres of trees had been felled to give free range to artillery, and at key positions along the front men were constantly on guard at their battle stations. Camps had sprung up like mushrooms in the open countryside, and here troops in and out of uniform could be seen almost incessantly engaged in drill.

By June 23, Beauregard was able to advise the Confederate Secretary of War that, in consequence of large reinforcements lately received, he had been able to divide his forces into six brigades commanded by Bonham, Ewell, D. R. Jones, Terrett, Cocke, and Early. Advance detachments had been stationed at key points including Centreville, Fairfax Court House, Germantown, the junction of the Old Braddock Road with the Fairfax Court House Road, and at Sangster’s Crossroads. With the main body of his troops partially intrenched along Bull Run, from Union Mills to the Stone Bridge, Beauregard watched closely the Federal preparations for an advance.

As the tension mounted, alarms occurred with increasing frequency. Bootless, hatless, and coatless men often dashed to assembly sounded by the “thump, thump of the big drums.” Rumors of the Federal advance “filled every breeze.” In a dispatch, dated July 9, Beauregard informed President Davis: “Enemy’s force increasing, and advancing daily this side of Potomac. He will soon attack with very superior numbers. No time should be lost in re-enforcing me here with at least ten thousand men—volunteers or militia.”

On the 17th Beauregard telegraphed President Davis informing him of an attack on his outposts and requesting that he send reinforcements “at the earliest possible moment.” Confronted with this crisis, Davis acted quickly. Advising Beauregard of the dispatch of reinforcements of Hampton’s Legion, McRae’s regiment, and two battalions of Mississippi and Alabama troops, he ordered Holmes’ troops up from Fredericksburg. The same day, through his adjutant, he sent the following dispatch to Johnston in Winchester:

RICHMOND, July 17, 1861.

General J. E. JOHNSTON, WINCHESTER, Va.:

General Beauregard is attacked. To strike the enemy a decisive blow a junction of all your effective force will be needed. If practicable, make the movement, sending your sick and baggage to Culpeper Court-House either by railroad or by Warrenton. In all the arrangements exercise your discretion.

S. COOPER, Adjutant and Inspector General.

Realizing that Harper’s