Manassas, Virginia, is thirty miles south of Washington, D.C., and the defenses that protected the city during the Civil War. Manassas was a key railroad junction during the Civil War and hence a likely place for two major battles of the war. The Confederates called the battles Manassas 1 and 2 (named after the closest town), and the Union called the battles Bull Run 1 and 2 (named after a nearby stream).
The public believed that the war would be short and came to the battle site on July 21, 1861, to watch the Union army quickly defeat the Confederates. The public's belief in a short war was also reflected in the six hastily constructed forts built around Washington, D.C. These forts were Corcoran, Runyon, Albany, Ellsworth, Bennett, and Haggerty. At the time, Forts Ellswoth protected Alexandria proper. Forts Corcoran, Bennett, and Haggerty protected the aqueduct leading to Georgetown, while Forts Runyon and Albany covered the approaches to Long Bridge.
Despite the arrival of 35,000 Union troops, the curiosity seekers did not see much military action. The closest that the civilian onlookers came to the battlefield was about one mile east of Stone Bridge over Bull Run, where a ridge offered a good vantage point. Most, however, ventured no farther than the area around Centreville, about five miles from the battlefield.
The battle began at dawn and around noon the Union troops stopped their advance to reorganize a new attack. During the midday lull, the Confederate reinforcements began arriving on Henry Hill, and took position to contest the Federals' advance on Manassas Junction. When the Union advance resumed around 2:00 p.m., the Federals launched repeated attacks to drive the Confederates out of their position on the hill. Unable to gain the upper hand on Henry Hill, McDowell directed his last available brigade to extend the army's right onto nearby Chinn Ridge, in an effort to flank the Confederate force on Henry Hill. However, these Federal troops encountered Confederate reinforcements, which forced them to withdraw, leading to the army's retreat from the battlefield.