Battle of First Bull Run

Effect on Union and subsequent events

Three months after the First Battle of Bull Run, Union forces suffered another, smaller defeat at the Battle of Ball's Bluff, near Leesburg, Virginia. The perceived military incompetence at both battles led to the establishment of the Joint Committee on the Conduct of the War, a congressional body created to investigate Northern military affairs. Concerning the Battle of First Bull Run, the committee listened to testimony from a variety of witnesses connected with McDowell's army. Although the committee's report concluded that the principal cause of defeat was Patterson's failure to prevent Johnston from reinforcing Beauregard, Patterson's enlistment had expired a few days after the battle, and he was no longer in the service. The Northern public clamored for another scapegoat, and McDowell bore the chief blame. On July 25, he was relieved of army command and replaced by Maj. Gen. George B. McClellan, who would soon be named general-in-chief of all the Union armies. McDowell was also present to bear significant blame for the defeat of Maj. Gen. John Pope's Army of Virginia by Gen. Robert E. Lee's Army of Northern Virginia thirteen months later, at the Second Battle of Bull Run.