July 21, 1861 – Union and Confederate troops clash outside Manassas, VA, in the first major engagement of the Civil War, the First Battle of Bull Run.
The battle began when the 35,000 Union soldiers marched from Washington, D.C. to the 20,000 strong Confederate army along a river known as Bull Run. After battling for most of the day, the rebels were able to rally and break through the Union's defenses, sending the leaders into a retreat towards Washington.
This victory gave the Confederates hope, and instilled a fear in the Union soldiers and supporters that the war would not end easily or quickly.
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