John G. Nicolay, The Outbreak of Rebellion

[167] That was the day before we left Bunker Hill. Then Colonel Porter asked to have Colonel Abercrombie and Colonel Thomas sent for and consulted as to the best manner to carry out his wishes. He consented, and they came, and after half an hour they dissuaded him from it.

With his intentions thus changed, Patterson late that night ordered a retrograde movement; and the next day, July 17th, his army marched to Charlestown-nominally as a flank movement, but practically in retreat, since it about doubled the distance between himself and the enemy. It adds neither excuse nor credit to himself or his advising subordinates that, as a partial justification, they had gulped down an absurd rumor about the enemy being forty thousand strong, without taking any efficient means to ascertain its correctness. And so lifeless and inefficient had the whole army become under such influences and management, that not till July 20th did Patterson learn the humiliating fact that he had wrecked the fair military reputation of a lifetime by permitting the enemy to escape through utterly inexcusable lack of energy and want of judgment. And if that reflection could be still further embittered, it was done by the early realization that his stupendous blunder had lost to the Union cause the first important battle of the war.

Johnston was at Winchester, in daily anticipation of Patterson's attack, when, a little after midnight of July 17th, he received orders from the Confederate authorities to go at once to the help of Beauregard. Just twenty-four hours had elapsed since Patterson's order to retreat, and the Union army was already at Charlestown. By nine o'clock on the morning of July 18th, Johnston's scouts brought him reports indicating clearly the actual situation. At noon of that day he had his whole effective force of nine thousand men on the march; at nightfall his advance passed through Ashby's