John G. Nicolay, The Outbreak of Rebellion

[172] North, eager to wipe out national insult and vindicate national authority, was impatient of what seemed tedious delay. The echoes of the Sumter bombardment were yet in the air; the blood on the Baltimore paving-stones was crying loudly to heaven. For half a century the nation had felt no close experience of war. The conquests of peace had grown almost miraculous in speed and certainty. Rivers and mountains, distance and time, had become the obedient ministers of creative ingenuity and bold enterprise. Forgetting that the achievements of peace encountered the opposing obstacles, not of man, but of nature alone, the North demanded speedy as well as signal redress. It saw rebellion enthroned in the capital of Virginia; it saw a numerous Union army gathered at Washington; the newspapers raised the cry of “On to Richmond;” and the popular heart beat in quick and well-nigh unanimous response to the slogan. Latterly a detachment sent out by General Butler from Fortress Monroe had met a repulse at Great Bethel, and near Washington a railroad-train under General Schenck had run into an ambush at Vienna station; both were trifling losses, but at the moment supremely irritating to the pride of the North, and the fires of patriotic resentment once more blazed up with fresh intensity.

General Scott's first project of an expedition against Manassas was made about the beginning of June, the object then being not to fight a battle, but merely make a threatening diversion to aid Patterson. There were at that time only some six thousand rebels at Manassas, according to Beauregard's report. Before the design could take final shape, Johnston had evacuated Harper's Ferry, and Patterson's first movement was thereby terminated. This occurred about the middle of June.

From that time on, the plan grew into the idea of a larger