The Battle of Blackburn's Ford took place on July 18, 1861, in Prince William County and Fairfax County, Virginia, as part of the First Manassas Campaign of the American Civil War. A Union brigade was ordered to probe the Confederate defenses along Bull Run to locate the Confederate left. At Blackburn's Ford, the brigade attempted to cross but Confederate fire broke up the attack and Union commanders decided to cross the creek farther upstream.