Nevertheless Burnside, reckless of any consequences that might follow, was determined that night to renew the battle on the following morning, himself leading his own former corps, the Ninth, in still another desperate attempt to carry Marye's Heights. Earnest protests and persuasions succeeded at last in inducing him to abandon this purpose, and after remaining inactive for a day on the bank of the river, he withdrew his army, under cover of night, to the other side of the river and the fearfully disastrous Fredericksburg campaign was at an end. Military critics have wondered much that Lee, whose loss in the battle had been only 5,309 men, and whose troops were almost wild with the enthusiasm of victory, permitted his badly beaten adversary to remain unmolested on the southern bank of the stream for twenty-four hours and then quietly to retire. Burnside's position and the condition of his army strongly invited attack. He had a wide and deep river behind him, with only a frail pontoon bridge spanning it. Had he been defeated there by assault on the part of the victors there would have been no way of escape open to him. Destruction or surrender must have followed. On the other hand, his force still heavily outnumbered Lee's and it was in no way demoralized. Defeated and discouraged as it was its spirit was unbroken, and had Lee left his works and assailed it in the open, the issue of the conflict might have been very uncertain. It is alleged that Lee's lieutenants urged a tempestuous assault, and that Lee's chief reason for rejecting the advice was born of his hope that Burnside would himself on the next day renew the attempt to dislodge the Confederates from their well-nigh impregnable position. However that may be, Lee did not in fact assume the offensive; Burnside retired during darkness to the farther side of the river and the two armies settled themselves in winter quarters, Lee presently sending large bodies of men to the southwest to reinforce the armies there, where active warfare was in progress, and still more active warfare threatened. The military operations of the season that thus closed had been in every way remarkable. Four distinct campaigns had been fought, all of them severe, and all marked by brilliant strategy and heroic conduct on the part of the troops on either side. McClellan's siege of Richmond, which had filled the South with gloomy apprehension, had been broken in a series of bloody and impressive battles, and the Army of the Potomac had been forced to withdraw for the defense of Washington. Pope's campaign with his Army of Virginia had been conspicuously brought to naught by brilliant strategy and desperate fighting.