Black and white photo of Irvin McDowell.

Brigadier General Irvin McDowell commanded Union forces during the First Battle of Bull Run. [National Archives]

First Battle of Bull Run Quick Facts

July 21, 1861

Facts About Bull Run, First Battle of

Also known as: First Battle of Bull Run, Battle of Manassas I, First Battle of Manassas

Date: July 21, 1861.

Location: Fairfax County And Prince William County, Virginia

Campaign: Manassas

Principal Union commander: Brigadier General Irvin McDowell.

Principal Confederate commanders: Brigadier General Joseph E. Johnston and Brigadier General P.G.T. Beauregard.

Union forces engaged: Army of Northeastern Virginia.

Confederate forces engaged: Army of the Potomac and Army of the Shenandoah.

Number of Union forces engaged: Roughly 18,000.

Number of Confederate forces engaged: Roughly 18,000.

Estimated Union casualties: 2,708 (481 killed; 1,011 wounded; and 1,216 missing)

Estimated Confederate casualties: 1,982 (387 killed; 1,582 wounded; and 13 missing)

Result: Confederate victory.

Confederate Colonel Thomas J. Jackson earned his nickname, “Stonewall” at the First Battle of Bull Run when his brigade of Virginia volunteers stood their ground in the face of a strong Union attack.

Confederate States of America President Jefferson Davis promoted Brigadier General P.G.T. Beauregard to the rank of full general the day after the First Battle of Bull Run.

Northerners blamed Brigadier General Irvin McDowell for the Union defeat and he was soon replaced by Major General George B. McClellan, who was named general-in-chief of all Union armies.

The battle has two names because the Federal frequently named battles for creeks or rivers that played a role in the fighting, while Confederates used the names of nearby towns or cities.

The redeployment of Stonewall Jackson’s brigade from the Shenandoah Valley to reinforce the Confederate line at Manassas was the first time that the railroad was used for strategic transportation in war.

Irvin McDowell’s Union Army of Northeastern Virginia was the largest army ever assembled on the North American continent up to that date.

Mrs. Judith Henry (killed) and her African-American maidservant (wounded) became the first civilian casualties of the American Civil War during the First Battle of Bull Run.

Citation Information

The following information is provided for citations.

  • Article Title Bull Run, First Battle of Quick Facts
  • Coverage July 21, 1861
  • Author
  • Keywords first battle of bull run, first battle of manassas
  • Website Name American History Central
  • Access Date January 18, 2021
  • Publisher R.Squared Communications, LLC
  • Original Published Date
  • Date of Last Update November 16, 2020