July 18, 1861 – The Federal Army of Northeastern Virginia arrived at Centreville, unaware that troops of the Confederate Army of the Shenandoah were en route by rail to reinforce their outnumbered comrades at Manassas.
By the 18th, it had taken the Federals two days to march 22 miles in the sweltering 90-degree heat. Major General Irvin McDowell, army commander, directed a reconnaissance in force led by Brigadier General Daniel Tyler and Colonel Israel B. Richardson, with orders not to bring on a general engagement. They advanced toward Blackburn’s Ford on Bull Run to probe near the Confederate right-center, but they went too far, and skirmishing erupted with Confederates defending both Blackburn’s and Mitchell’s fords.
Richardson ordered a withdrawal when Colonel James Longstreet’s three Confederate brigades stopped his 1st Massachusetts and two cannon. But Tyler defied McDowell’s orders by sending more infantry and artillery into the fight. Longstreet counterattacked with support from General Jubal A. Early, but the green troops bungled the effort. Nevertheless, the Confederates prevented the Federals from reaching Bull Run, and both sides fell back to reorganize. The Federals suffered 83 casualties, while Confederates lost 15 killed and 53 wounded.
Colonel William T. Sherman, whose brigade was part of Tyler’s force, described the combat: “From our camp, at Centreville, we heard the cannonading, and then a sharp musketry-fire… We marched the three miles at the double-quick, arrived in time to relieve Richardson’s brigade, which was just drawing back from the ford, worsted, and stood for half an hour or so under fire of artillery, which killed four or five of my men…”
Confederates celebrated this minor victory, as President Jefferson Davis wired Brigadier General P.G.T. Beauregard, overall commander: “God be praised for your successful beginning.” McDowell expressed annoyance at Tyler’s disobedience, and the Federals had been forced to retreat. However, they gained important intelligence regarding Confederate strength, and from this McDowell deemed the Confederate front too strong to penetrate. He spent another two days collecting supplies and reconnoitering the Confederate lines before finally deciding on a flank attack.
While Beauregard’s Confederate Army of the Potomac held an eight-mile line along Bull Run, Major General Joseph E. Johnston prepared to reinforce him with his 11,000-man Army of the Shenandoah. Johnston wrote to Adjutant General Samuel Cooper on the 18th: “(Federal) General (Robert) Patterson, who had been at Bunker Hill since Monday, seems to have moved yesterday to Charlestown, 23 miles to the east of Winchester. Unless he prevents it, we shall move toward General Beauregard to-day…”
Patterson’s move to Charles Town made him too far from Johnston’s forces at Winchester to stop them from reinforcing Beauregard. Patterson had planned to attack the Confederates on the 18th, but he reported to General-in-Chief Winfield Scott that not only had Johnston been neutralized at Winchester, but “he had also been reinforced.” Patterson also expressed reluctance to attack because his 90-day enlistments would expire soon, and he complained that orders from Washington did not clearly state whether he should attack or merely keep Johnston occupied.
Before Patterson could get his Federals in motion to do anything, Colonel J.E.B. “Jeb” Stuart’s Confederate cavalry created a diversion in their front near Charles Town. Meanwhile, Johnston had his troops moving out of Winchester by 12 p.m., with Brigadier General Thomas J. Jackson’s brigade in the lead. Officers read a general proclamation to their men, explaining that Beauregard needed help to repel an impending attack.
The troops, initially excited about going into battle, soon became exhausted by the eastward march through the Blue Ridge Mountains. The Confederates stopped at Piedmont, the nearest stop on the Manassas Gap Railroad, and boarded train cars to finish their journey to Beauregard. This marked the first large-scale strategic troop movement by railroad in military history. By day’s end, four of Johnston’s brigades totaling some 8,300 men were on eastbound trains.
Meanwhile, Scott in Washington received intelligence that Johnston had given Patterson the slip. Scott asked his general: “Has he not stolen a march and sent reinforcements to Manassas Junction?”
McDowell spent July 19th resupplying and reorganizing his army at Centreville, as well as reworking his plan of attack based on yesterday’s engagement at Blackburn’s Ford. Stragglers trickled in and out of camps throughout the day. Meanwhile, Beauregard spent the day strengthening his defenses along Bull Run.
Johnston continued moving his army eastward on the eight-hour train ride from the Piedmont Station to Manassas Junction. Excessive traffic on the single-track railroad prevented more reinforcements from arriving, but they would be coming soon. Jackson’s men arrived near 4 p.m., and their commander surprised Beauregard and his staff by entering their headquarters at the Wilmer McLean house and announcing his arrival.
During the day, a messenger delivered instructions for Johnston from Beauregard to move his forces via Aldie and arrange them on the Federal right flank. Johnston disregarded this, staying with his railroad transport plan. He then wrote to President Davis, asking him to clarify whether Johnston or Beauregard would be the ranking officer over the combined force. Davis made it clear that Johnston outranked Beauregard:
“You are a general in the Confederate Army, possessed of the power attaching to that rank. You will know how to make the exact knowledge of Brigadier-General Beauregard, as well of the ground as of the troops and preparation, avail for the success of the object in which you cooperate. The zeal of both assures me of harmonious action.”
Johnston arrived at Manassas Junction around 12 p.m. on the 20th with another 1,400 reinforcements in three brigades led by Colonel Francis S. Bartow, and Brigadier Generals Barnard E. Bee and Edmund Kirby Smith. By this time, some 9,000 of Johnston’s Confederates had traveled 50 miles by rail in just two days. Brigadier General Theophilus H. Holmes’s brigade also arrived from Aquia Creek, as did Colonel Wade Hampton’s Legion.
Since Beauregard had been at Manassas for nearly two months and had better knowledge of the region, Johnston allowed him to retain top command. Johnston also approved his plan to mass the Confederates on the right and attack the Federal left, despite its complexity for such green troops. Ironically, McDowell also finalized a plan to move right and attack the Confederate left. Had both armies moved at the same time, they would have swung in a circle. But if one moved before the other, the moving army would put the other on the defensive.
McDowell initially planned to move out on the 20th, but delays in supply delivery compelled him to postpone until the next day. Secretary of War Simon Cameron, visiting McDowell’s headquarters, sent a report on the army to President Lincoln. Other politicians and notable civilians came out from Washington to mingle with the Federals and witness the impending battle. Most Federals expressed confidence, despite hearing the train whistles at Manassas Junction; they believed that the trains carried small bodies of troops from Richmond, not Johnston’s entire army.
McDowell met with his division and brigade commanders that night. He issued final orders for tomorrow’s action, basing his decision to assault the enemy left on the repulse at Blackburn’s Ford two days ago. The Federals would move against an unguarded crossing on the Confederate left, with one division feigning an attack on the Stone Bridge while two divisions crossed Bull Run north of the bridge, near Sudley Springs.
Although McDowell sought no advice, some officers expressed concerns that Johnston may have reinforced Beauregard. McDowell, who himself had originally advised against such a hasty campaign as this, would not consider any further objections; the time for fighting had arrived. The Federals began moving in the evening darkness.
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