John G. Nicolay, The Outbreak of Rebellion

At ten o'clock Hunter's advance emerged from the woods into open fields, about a mile north of the Warrenton turnpike, the scattering shots of the skirmishers having already opened the conflict. On both sides everything was raw and awkward-officers and men, staff and line. There was undue excitement and impetuosity, mixed with unnecessary confusion and delay. None of the reports specify how the battle began; the mere momentum of the march seems to have carried the advance regiments under the first shower of rebel shells and bullets at distances varying from five hundred to one thousand yards. A preliminary artillery duel sprang up, under which Burnside led his four regiments after his battery into the fields to the left of the Sudley road. With a little more deliberation and a united onset, these would easily have brushed away Evans' thin line; but, in the delay incident to the first actual experiment of battle, the rebels gained opportunity to bring up substantial reinforcements. Four regiments and two companies of Johnston's Army of the Shenandoah, under General Bee, hurried up and formed to the right and a little in advance of Evans' original line, while Imboden's battery of four guns took position on a hill in the rear, south of the Warrenton turnpike. Thus disposed, with little disparity in strength between attack and defence, the first stubborn contest of the day appears to have taken place, lasting perhaps from eleven o'clock till noon. The Union troops pressed forward with determined courage; the rebels resisted with such spirit that Burnside became apprehensive for his Rhode Island battery, and Sykes' battalion of regulars was sent to strengthen his left. By this time Hunter had sent Porter's brigade into the fields to the right of the Sudley road, where Griffin's battery could engage the rebel field-pieces; Heintzelman was hurrying up with an advance regiment and