The First Battle of Bull Run: Summary, Significance & Facts

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  • 0:01 What Was the First…
  • 0:37 Setting the Stage for War
  • 2:45 McDowell's Advance
  • 4:45 July 21, 1861
  • 7:29 Aftermath
  • 9:17 Lesson Summary
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Lesson Transcript
Instructor: Daniel Vermilya
The First Battle of Bull Run (also known as the First Manassas) was fought on July 21, 1861. It was the first major battle of the Civil War and resulted in a Confederate victory.

What Was the First Battle of Bull Run?

On July 21, 1861, just 30 miles outside of Washington, D.C., the unthinkable happened. Two armies, each composed of Americans, fought a day-long battle that resulted in nearly 5,000 casualties, which means almost 5,000 people were killed, wounded, missing, or captured. On that day, the United States forever changed. While the first shots of the Civil War were fired at Fort Sumter in April 1861, the events of that fateful July 21 comprised the first true battle of the war, The First Battle of Bull Run. Let's learn more about this important Civil War battle.

Setting the Stage for War

In the spring of 1861, war fever was gripping both the North and the South. The secession winter had ended with seven Southern states leaving the Union over the issue of slavery and forming the Confederate States of America. In March, Abraham Lincoln was inaugurated as the 16th president of the United States.

One month later, Confederate troops in Charleston, South Carolina, fired on Federal forces at Fort Sumter in Charleston Harbor. Lincoln soon called for 75,000 90-day volunteers to put down the rebellion, four more states left the Union to join the Confederacy, and war had begun. Yet, despite this war fever, there was little action in May and June. Nearly everyone assumed that there would be one great battle to decide the entire matter.

By July of 1861, the public demand for action was reaching a fever pitch. The Union Army of Northeastern Virginia, commanded by Brigadier General Irvin McDowell, was more than 30,000 men strong. 30 miles away from Washington, more than 20,000 Confederate troops under the command of Brigadier General P.G.T. Beauregard, the Confederate hero of Fort Sumter, were gathering together in preparation for the eagerly anticipated battle.

Beauregard's Confederates, labeled the Army of the Potomac (not to be confused with the Union army of the same name that was formed later in the war) were near Manassas Junction, a crucial railroad point that allowed them to remain connected to their supplies and other Confederate troops.

Many miles to the west, in the Shenandoah Valley, there was another Confederate army that could possibly come to Beauregard's aid. The Army of the Shenandoah, led by Confederate Brigadier General Joseph E. Johnston, was approximately 12,000 men strong; however, there was a problem. Johnston was facing off against a Union army of his own - that of Major General Robert Patterson. At 69 years old, Patterson was not an ideal choice for the important task of keeping Johnston occupied. McDowell wanted Johnston to stay where he was to prevent adding reinforcements to Beauregard's force. This would prove to be a crucial aspect of the upcoming battle.

McDowell's Advance

On July 16, McDowell began moving south from Washington. His intended target was the rail junction of Centreville, Virginia. As he was moving toward Manassas, Confederate forces began to sound the alarm. In the Shenandoah, Robert Patterson had proved unable to pin down Johnston's army. Johnston knew it was a risk to leave Patterson with open access to the Shenandoah, but he could not afford to allow Beauregard's army to be destroyed. Thus, for the first time in history, railroads were used to rush troops to the scene of a battle. Johnston began sending his army via rail to Manassas to bolster Confederate strength.

These reinforcements began arriving in Manassas on the morning of the 20th. Just two days earlier, on July 18, an opening skirmish of sorts occurred along Bull Run, a creek near the Confederate positions outside of Manassas. Union forces encountered Confederates near Blackburn's Ford. After a few hours, several hundred casualties had fallen in the skirmish, and Union forces pulled back. The first blood of Bull Run had been shed.

After this skirmish, McDowell formulated a battle plan to defeat the Confederates. Since the fight at Blackburn's Ford had occurred near the right flank of the Confederate positions, McDowell decided to move around to the Confederate left. Union forces would cross at the Sudley Springs Ford, north of the Confederate position. To mask this movement, Federal troops would also move across the Stone Bridge over Bull Run on the Warrenton Turnpike. By attacking at two points, McDowell could make sure to keep the Confederates right where he wanted them.

Conversely, Beauregard was planning to attack the Federal left flank as well. Beauregard wanted to move toward Centreville to either drive the Union troops back to Washington or cut them off from the Federal capital. Since each army would be attacking the other's left flank, if both had their way, they would have been turning continuously like a dog chasing its tail. Whoever attacked first would get the early advantage.

July 21, 1861

It was McDowell who moved first and had early success at Bull Run. On the morning of July 21, Federal forces crossed Bull Run at both places, catching the Confederates off guard. By mid-morning, the fighting centered on Matthews Hill, where, at first, only a single Confederate brigade attempted to stop the Federal flank attack. After delaying the attack, the Confederates were forced to fall back to Henry House Hill, where the 85-year-old widow Judith Henry lived. Henry's house was in the midst of the fighting that afternoon; she was killed by artillery fire later that day.

As the Confederates fell back to Henry House Hill, they began receiving reinforcements. Johnston soon arrived on the field with Beauregard, and they determined to hold the hillside. At this same time, as Confederate fortunes strengthened, Federal hopes began to fade. McDowell allowed a pause in the battle in order to bring up more troops. By failing to vigorously follow up his success thus far, McDowell allowed the Confederates a crucial pause to catch their breath.

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