It was not till the next morning, December 12, that the army began to cross, and the movement, made difficult by a dense fog, was by no means energetic.  Four of the six army corps were transferred during the day to the southern bank; but beyond a cavalry reconnaissance, which was checked by Stuart, there was no fighting, and to every man in the Federal ranks it was perfectly plain that the delay was fatal.

Lee, meanwhile, with ample time at his disposal and full confidence in the wisdom of his dispositions, calmly awaited the development of his adversary’s plans.  Jackson brought up A.P.  Hill and Taliaferro at noon, and posted them on Longstreet’s right; but it was not till that hour, when it had at last become certain that the whole Federal army was crossing, that couriers were dispatched to call in Early and D.H.  Hill.  Once more the Army of Northern Virginia was concentrated at exactly the right moment on the field of battle.* (* Lord Wolseley North American Review volume 149 page 282.)

Dec. 13.

Like its predecessor, December 13 broke dull and calm, and the mist which shrouded river and plain hid from each other the rival hosts.  Long before daybreak the Federal divisions still beyond the stream began to cross; and as the morning wore on, and the troops near Hazel Run moved forward from their bivouacs, the rumbling of artillery on the frozen roads, the loud words of command, and the sound of martial music came, muffled by the fog, to the ears of the Confederates lying expectant on the ridge.  Now and again the curtain lifted for a moment, and the Southern guns assailed the long dark columns of the foe.  Very early had the Confederates taken up their position.  The ravine of Deep Run, covered with tangled brushwood, was the line of demarcation between Jackson and Longstreet.  On the extreme right of the Second Corps, and half a mile north of the marshy valley of the Massaponax, where a spur called Prospect Hill juts down from the wooded ridge, were fourteen guns under Colonel Walker.  Supported by two regiments of Field’s brigade, these pieces were held back for the present within the forest which here clothed the ridge.  Below Prospect Hill, and running thence along the front of the position, the embankment of the Richmond and Potomac Railroad formed a tempting breastwork.  It was utilised, however, only by the skirmishers of the defence.  The edge of the forest, One hundred and fifty to two hundred yards in rear, looked down upon an open and gentle slope, and along the brow of this natural glacis, covered by the thick timber, Jackson posted his fighting-line.  To this position it was easy to move up his supports and reserves without exposing them to the fire of artillery; and if the assailants should seize the embankment, he relied upon the deadly rifles of his infantry to bar their further advance up the ascent beyond.