The Battle of Blackburn's Ford (also known as the Skirmish at Blackburn's Ford) took place on July 18, 1861, in the Confederate state of Virginia, as part of the Manassas campaign of the American Civil War. Union general Irvin McDowell's Army of Northeastern Virginia was marching south towards the Confederate capital of Richmond, and encountered the Confederate Army of the Potomac under the command of P. G. T. Beauregard. McDowell sent troops from Daniel Tyler's division to probe the Confederate defenses along Bull Run Creek to locate the Confederate left flank. At Blackburn's Ford, the Union troops attempted to cross but Confederate fire broke up the attack. The repulse at Blackburn's Ford led McDowell to seek to attack the Confederates at a different point along their line, leading to the First Battle of Bull Run three days later. Background On July 16, 1861, the untried Union Army of Northeastern Virginia under Brigadier General (Brig. Gen.) Irvin McDowell, 35,000 strong, marched out of the Washington, D.C., defenses to give battle to the Confederate Army of the Potomac, which was concentrated around the vital railroad junction at Manassas. Moving slowly, the army reached Fairfax Court House on July 17; the next day, McDowell ordered division commander Brig. Gen. Daniel Tyler to look for a fording point across Bull Run Creek and to "keep up the impression that we are moving on Manassas". The Confederates, about 22,000 men under the command of Brig. Gen. P.G.T. Beauregard, were concentrated near Bull Run Creek, with detachments spread north of the creek to observe the Union troops. When McDowell started his advance from Washington, the Confederate detachments slowly retreated and rejoined the main body. Beauregard expected to be attacked either on the 18th or the 19th near Mitchell's Ford; meanwhile, he continued to ask for reinforcements, especially from Joseph E. Johnston's army in the Shenandoah Valley. Battle On July 18, Tyler advanced to Centreville and was informed by local residents that the Confederates had retreated from the town. Milledge Bonham's troops in particular were reported to have retreated in the direction of Blackburn's Ford. Tyler then marched southeast to Mitchell's Ford and Blackburn's Ford, arriving at the latter about 11 a.m. Looking south across the stream, Tyler believed that the road to Manassas Junction was mostly clear, but he failed to see the Confederate brigade of Brig. Gen. James Longstreet concealed in the woods behind the