The First Battle of Bull Run | July 21, 1861 | HISTORY

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On July 21, 1861, in the first major land battle of the Civil War, a large Union force under General Irvin McDowell is routed by a Confederate army under General Pierre G.T. Beauregard.

Three months after the Civil War erupted at Fort Sumter, Union military command still believed that the Confederacy could be crushed quickly and with little loss of life. In July, this overconfidence led to a premature offensive into northern Virginia by General McDowell. Searching out the Confederate forces, McDowell led 34,000 troops—mostly inexperienced and poorly trained militiamen—toward the railroad junction of Manassas, located just 30 miles from Washington, D.C. Alerted to the Union advance, General Beauregard massed some 20,000 troops there and was soon joined by General Joseph Johnston, who brought some 9,000 more troops by railroad.