When George Cadwalader’s division crossed the Potomac River on June 16 at Williamsport, Maryland, north of Harpers Ferry without opposition, Gen. Patterson finally accepted the fact that Johnston had abandoned the place. Patterson began planning his next move, but his slow pace did not sit well with his superiors. Sitting in his office in Washington, Gen. Scott made a fateful decision: if Patterson did not move at once against Johnston, he would have to consider a command change. Scott fired off a dispatch ordering Patterson to send his Regular Army units (mostly artillery) to McDowell, along with a Rhode Island regiment under Col. Ambrose Burnside. Patterson vigorously protested, to no avail. Scott ended the discussion with a telegram: “We are pressed here. Send the troops that I have twice called for without delay.” Patterson complied. Scott was now convinced the major thrust against the Confederacy in Virginia must be delivered by McDowell.
The following day, Patterson received word that Johnston was approaching Harpers Ferry with an army that far exceeded his own. While untrue, the loss of his Regulars made Patterson even more hesitant and indecisive than usual. Without consulting Scott—whom he now considered unsympathetic to his army’s needs—Patterson on June 18 withdrew his command to the opposite side of the Potomac River at Williamsport. The withdrawal angered Scott, who immediately ordered Patterson back across the river. In another duel of wills, Patterson declined. He refused a second time on June 20. At one point during the exchange Patterson wired Scott that Johnston’s army numbered more than 25,000 men. Patterson’s adamant insistence that he was heavily outnumbered had the desired effect, and on June 25 Scott ordered Patterson to stay put.1
On June 28, Patterson’s army numbered about 14,000 men. It was organized into five brigades divided among two divisions, one under Maj. Gen. George Cadwalader and the other under Maj. Gen. William H. Keim. Gen. Johnston’s smaller Confederate army fielded fewer than 11,000 men in four brigades commanded by Brig. Gens. Barnard Bee, Thomas Jackson, and Kirby Smith, and Col. Arnold Elzey. Johnston was fortunate to have Col. James Ewell Brown (Jeb) Stuart and his 1st Virginia Cavalry. An additional infantry brigade of Georgians under Col. Francis Bartow would be added later.2
Jackson’s Brigade was detached from Johnston’s army on June 19 and sent to Martinsburg to destroy a large supply of railroad equipment stored there. Jackson had his command on the road at 5:00 p.m. and the men marched through half the night. After a few hours of rest they were back in column at dawn. When they reached this staunchly Unionist town Jackson reported that there was time to move the equipment, but Johnston insisted on its destruction. Overruled, Jackson fired the equipment. This was but one of a growing number of incidents between the cautious Johnston and the more aggressive Jackson. The Virginians set to work, destroying 56 locomotives and tenders and 305 coal cars, firing round houses and machine shops, and ripping up miles of track.3
Gathering his forces, Patterson decided on June 30 to once again cross the Potomac at Williamsport the following day. The move did not begin until 4:00 a.m. on July 2. When he learned of the attempt, Jackson pondered Johnston’s orders to retire if the enemy approached his front in force. He decided instead to send a regiment and a battery of artillery to Falling Waters to reconnoiter and possibly resist the movement. Although he managed to slow the crossing for a short time, the overwhelming size of the Federal army, coupled with Johnston’s clear orders, resulted in Jackson’s slow withdrawal.
Demonstrating glimpses of the aggressiveness that would be evident on future fields, Jackson called up two more regiments and, together with Stuart’s cavalry, tried to cut off a column of Federal troops. When three Federal regiments were found in his front and an enemy brigade began to creep around his flank, however, Jackson wisely withdrew to Darksville on the road to Winchester, where he combined with the rest of Johnston’s army about dawn on July 3.4