William Swinton, Campaigns of the Army of the Potomac

Two days afterwards a general advance was made in the direction of Richmond. Whatever force of the enemy was encountered was pressed back until dark, when the Confederates took position on the left bank of Proctor's Creek. Next morning (13th) the enemy withdrew from the creek to an intrenched line in the rear. This line, if adequately held, would have been difficult to carry by assault; but General Gillmore succeeded in turning it, and held its extreme right. The possession of this line, however, only revealed the enemy holding an interior line of works, with a bastion salient on an eminence completely commanding the position gained. The flanks fell back on the Confederates' left to the James River and Drury's Bluff, and on their right extended in a northwesterly direction beyond any point visible. The prong or arm of the works which General Gillmore had turned ran into this second line at the bastion salient before mentioned. Butler's force was much strung out, and an assault ordered for the next morning had to be abandoned for the want of available troops to form a column. It was then determined to attack on the morning of the 16th.

The night of the 15th every thing was still. A thin film of clouds slightly obscured the sky, but it was not so heavy as to interfere seriously with the moonlight, and the heavens gave no token of what was presently to be seen. Before dawn a dense fog, arising from the margin of the James, overspread the whole face of the country with so opaque a pall that a horseman was not visible at a distance of ten yards. In the thick of this, and before dawn, the sleeping camp was suddenly aroused by a savage outburst of musketry and artillery fire along the whole line. Beauregard had taken advantage of the fog, and had begun the execution of a plan of offensive action which, under the circumstances, threatened fatal results to the Union force. Butler's force was disposed along a front excessively extended, and though General Smith endeavored to reach as far as possible by drawing out his corps in one thin line, there was still a full mile and a half of open, undulating country between his right flank and the