American Civil War: First Battle of Bull Run

First Battle of Bull Run

Kurz & Allison / Public Domain


The First Battle of Bull Run was fought on July 21, 1861, during the American Civil War (1861–1865), and was the first major battle of the conflict. Advancing into northern Virginia, Union and Confederate troops clashed near Manassas Junction. Though Union forces held an early advantage, an overly-complex plan and the arrival of Confederate reinforcements led to their collapse and they were driven from the field. The defeat shocked the public in the North and quashed hopes for a swift resolution to the conflict. 


In the wake of the Confederate attack on Fort Sumter, President Abraham Lincoln called for 75,000 men to aid in putting down the rebellion. While this action saw additional states leave the Union, it also began a flow of men and material into Washington, DC. The growing body of troops in the nation's capital was ultimately organized into the Army of Northeastern Virginia. To lead this force, General Winfield Scott was compelled by political forces to select Brigadier General Irvin McDowell. A career staff officer, McDowell had never led men in combat and in many ways was as green as his troops.

Assembling around 35,000 men, McDowell was supported to the west by Major General Robert Patterson and a Union force of 18,000 men. Opposing the Union commanders were two Confederate armies led by Brigadier Generals P.G.T. Beauregard and Joseph E. Johnston. The victor of Fort Sumter, Beauregard led the 22,000-man Confederate Army of the Potomac which was centered near Manassas Junction. To the west, Johnston was tasked with defending the Shenandoah Valley with a force of around 12,000. The two Confederate commands were linked by the Manassas Gap Railroad which would allow one to support the other if attacked.

Armies & Commanders


  • Brigadier General Irvin McDowell
  • 28,000-35,000 men


  • Brigadier General P.G.T. Beauregard
  • Brigadier General Joseph E. Johnston
  • 32,000-34,000 men

Strategic Situation

As Manassas Junction also provided access to the Orange & Alexandria Railroad, which led into the heart of Virginia, it was critical that Beauregard hold the position. To defend the junction, Confederate troops began fortifying the fords to the northeast over Bull Run. Aware that the Confederates could shift troops along the Manassas Gap Railroad, Union planners dictated that any advance by McDowell be supported by Patterson with the goal of pinning Johnston in place. Under heavy pressure from the government to win a victory in northern Virginia, McDowell departed Washington on July 16, 1861.

McDowell's Plan

Moving west with his army, he intended to make a diversionary attack against the Bull Run line with two columns while a third swung south around the Confederate right flank to cut their line of retreat to Richmond. To ensure that Johnston would not enter the fray, Patterson was ordered to advance up the Valley. Enduring extreme summer weather, McDowell's men moved slowly and camped at Centreville on July 18. Searching for the Confederate flank, he dispatched Brigadier General Daniel Tyler's division south. Advancing, they fought a skirmish at Blackburn's Ford that afternoon and were forced to withdraw (Map).

Frustrated in his efforts to turn the Confederate right, McDowell altered his plan and began efforts against the enemy's left. His new plan called for Tyler's division to advance west along the Warrenton Turnpike and conduct a diversionary assault across the Stone Bridge over Bull Run. As this moved forward, the divisions of Brigadier Generals David Hunter and Samuel P. Heintzelman would swing north, cross Bull Run at Sudley Springs Ford, and descend on the Confederate rear. To the west, Patterson was proving a timid commander. Deciding that Patterson would not attack, Johnston began shifting his men east on July 19.

The Battle Begins

By July 20, most of Johnston's men had arrived and were situated near Blackburn's Ford. Assessing the situation, Beauregard intended to attack north towards Centreville. This plan was preempted early on the morning of July 21 when Union guns began shelling his headquarters at the McLean House near Mitchell's Ford. Despite having crafted an intelligent plan, McDowell's attack was soon beset with issues due to poor scouting and the overall inexperience of his men. While Tyler's men reached the Stone Bridge around 6:00 AM, the flanking columns were hours behind due to poor roads leading to Sudley Springs.

Early Success

Union troops began crossing the ford around 9:30 AM and pushed south. Holding the Confederate left was the 1,100-man brigade of Colonel Nathan Evans. Dispatching troops to contain Tyler at the Stone Bridge, he was alerted to the flanking movement by a semaphore communication from Captain E.P. Alexander. Shifting around 900 men northwest, he assumed a position on Matthews Hill and was reinforced by Brigadier General Barnard Bee and Colonel Francis Bartow. From this position, they were able to slow the advance of Hunter's lead brigade under Brigadier General Ambrose Burnside (Map).

This line collapsed around 11:30 AM when the brigade of Colonel William T. Sherman struck their right. Falling back in disorder, they assumed a new position on Henry House Hill under the protection of Confederate artillery. Though possessing momentum, McDowell did not push forward but instead brought up artillery under Captains Charles Griffin and James Ricketts to shell the enemy from Dogan Ridge. This pause allowed Colonel Thomas Jackson's Virginia Brigade to reach the hill. Positioned on the reverse slope of the hill, they were unseen by the Union commanders.

The Tide Turns

Advancing his guns without support, McDowell sought to weaken the Confederate line before attacking. After more delays during which the artillerymen took heavy losses, he began a series of piecemeal attacks. These were repulsed with the Confederate counterattacking in turn. In the course of this action, Bee exclaimed, "There is Jackson standing like a stone wall." Some controversy exists regarding this statement as some later reports claimed that Bee was upset at Jackson for not moving to his brigade's aid faster and that "stone wall" was meant in a pejorative sense. Regardless, the name stuck to both Jackson and his brigade for the remainder of the war. In the course of the fighting, there were several issues of unit recognition as uniforms and flags had not been standardized (Map).

On Henry House Hill, Jackson's men turned back numerous attacks, while additional reinforcements arrived on both sides. Around 4:00 PM, Colonel Oliver O. Howard arrived on the field with his brigade and took a position on the Union right. He soon came under heavy attack by Confederate troops led by Colonels Arnold Elzey and Jubal Early. Shattering Howard's right flank, they drove him from the field. Seeing this, Beauregard ordered a general advance which caused the tired Union troops to begin a disorganized retreat towards Bull Run. Unable to rally his men, McDowell watched as the retreat became a rout (Map).

Seeking to pursue the fleeing Union troops, Beauregard and Johnston initially hoped to reach Centreville and cut off McDowell's retreat. This was thwarted by fresh Union troops which successfully held the road to the town as well as a rumor that a new Union attack was in the offing. Small groups of Confederates continued the pursuit, capturing Union troops as well as dignitaries who had come from Washington to watch the battle. They also succeeded in hampering the retreat by causing a wagon to overturn on the bridge over Cub Run, blocking Union traffic.


In the fighting at Bull Run, Union forces lost 460 killed, 1,124 wounded, and 1,312 captured/missing, while the Confederates incurred 387 killed, 1,582 wounded, and 13 missing. The remnants of McDowell's army flowed back into Washington and for some time there was concern that the city would be attacked. The defeat stunned the North which had expected an easy victory and led many to believe that the war would be long and costly.

On July 22, Lincoln signed a bill calling for 500,000 volunteers and efforts began to rebuild the army. These ultimately came under the commander of Major General George B. McClellan. Reorganizing the troops around Washington and incorporating newly-arriving units, he constructed what would become the Army of the Potomac. This command would serve as the Union's primary army in the east for the rest of the war.

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Your Citation
Hickman, Kennedy. "American Civil War: First Battle of Bull Run." ThoughtCo, Aug. 27, 2020, Hickman, Kennedy. (2020, August 27). American Civil War: First Battle of Bull Run. Retrieved from Hickman, Kennedy. "American Civil War: First Battle of Bull Run." ThoughtCo. (accessed June 4, 2023).