All day, during the 9th, the two armies were constructing breastworks along their entire fronts, and these works, from the Rapidan to the banks of the Chickahominy, remain yet in existence.  On the evening of this day a Federal force was thrown across the Po, on the Confederate left, but soon withdrawn; and on the 10th a similar movement took place near the same point, which resulted in a brief but bloody conflict, during which the woods took fire, and many of the assaulting troops perished miserably in the flames.  The force was then recalled, and, during that night and the succeeding day, nothing of importance occurred, although heavy skirmishing and an artillery-fire took place along the lines.

On the morning of the 12th, at the first dawn of day, General Grant made a more important and dangerous assault than any yet undertaken in the campaign.  This was directed at a salient on General Lee’s right centre, occupied by Johnson’s division of Ewell’s corps, and was one of the bloodiest and most terrible incidents of the war.  For this assault General Grant is said to have selected his best troops.  These advanced in a heavy charging column, through the half darkness of dawn, passed silently over the Confederate skirmishers, scarcely firing a shot, and, just as the first streak of daylight touched the eastern woods, burst upon the salient, which they stormed at the point of the bayonet.  In consequence of the suddenness of the assault and the absence of artillery—­against whose removal General Johnston is stated to have protested, and which arrived too late—­the Federal forces carried all before them, and gained possession of the works, in spite of a stubborn and bloody resistance.

Such was the excellent success of the Federal movement, and the Southern line seemed to be hopelessly disrupted.  Nearly the whole of Johnson’s division were taken prisoners—­the number amounting to about three thousand—­and eighteen pieces of artillery fell into the hands of the assaulting column.

The position of affairs was now exceedingly critical; and, unless General Lee could reform his line at the point, it seemed that nothing was left him but an abandonment of his whole position.  The Federal army had broken his line; was pouring into the opening; and, to prevent him from concentrating at the point to regain possession of the works, heavy attacks were begun by the enemy on his right and left wings.  It is probable that at no time during the war was the Southern army in greater danger of a bloody and decisive disaster.

At this critical moment General Lee acted with the nerve and coolness of a soldier whom no adverse event can shake.  Those who saw him will testify to the stern courage of his expression; the glance of the eye, which indicated a great nature, aroused to the depth of its powerful organization.  Line of battle was promptly formed a short distance in rear of the salient then in the enemy’s possession,