It was now about one o'clock, and nearly three hours had been spent in a bitter and bloody contest across the narrow stream. The successive efforts to carry the bridge had been as closely following each other as possible. Each had been a fierce combat, in which the men with wonderful courage had not easily accepted defeat, and even, when not able to cross the bridge, had made use of the walls at the end, the fences, and every tree and stone as cover, while they strove to reach with their fire their well-protected and nearly concealed opponents. The lulls in the fighting had been short, and only to prepare new efforts. The severity of the work was attested by our losses, which, before the crossing was won, exceeded 500 men, and included some of our best officers, such as Colonel Kingsbury of the Eleventh Connecticut, Lieutenant-Colonel Bell of the Fifty-first Pennsylvania, and Lieutenant-Colonel Coleman of the Eleventh Ohio, two of them commanding regiments. [Footnote: Official Records, vol. xix. pt. i. p. 427.] The proportion of casualties to the number engaged was much greater than common; for the nature of the combat required that comparatively few troops should be exposed at once, the others remaining under cover. Our next task was to prepare to hold the heights we had gained against the return assault of the enemy which we expected, and to reply to the destructive fire from the enemy's abundant artillery. Light batteries were brought over and distributed in the line. The men were made to lie down behind the crest to save them from the concentrated cannonade which the enemy opened upon us as soon as Toombs's regiments succeeded in reaching their main line. But McClellan's anticipation of an overwhelming attack upon his right was so strong that he determined still to press our advance, and sent orders accordingly. The ammunition of Sturgis's and Crook's men had been nearly exhausted, and it was imperative that they should be freshly supplied before entering into another engagement. Sturgis also reported his men so exhausted by their efforts as to be unfit for an immediate advance. On this I sent to Burnside the request that Willcox's division be sent over, with an ammunition train, and that Sturgis's division be replaced by the fresh troops, remaining, however, on the west side of the stream as support to the others. This was done as rapidly as was practicable, where everything had to pass down the steep hill-road and through so narrow a defile as the bridge. [Footnote: As a mode of ready reckoning, it is usual to assume that a division requires an hour to march past a given point by the flank. With the crossing of an ammunition train, the interval of time is more than accounted for.] Still, it was three o'clock before these changes and preparations could be made. Burnside had personally striven to hasten them, and had come over to the west bank to consult and to hurry matters, and took his share of personal