From this, the Lacy House, which Sumner had made his headquarters, he directed the advance of his right grand division of the Army of the Potomac on December 11, 1862. Little did he dream that his men of the Second Corps were to bear the brunt of the fighting and the most crushing blow of the defeat on the 13th. Soon after three o'clock on the morning of the 11th the columns moved out with alacrity to the river bank and before daybreak, hidden at first by the fog, the pontoniers began building the bridges. Confederate sharpshooters drove off the working party from the bridge below the Lacy House and also from the middle bridge farther down. As the mist cleared, volunteers ferried themselves over in the boats and drove off the riflemen. At last, at daybreak of the 12th, the town of Fredericksburg was occupied, but the whole of another foggy day was consumed in getting the army concentrated on the western shore. Nineteen batteries (one hundred and four guns) accompanied Sumner's troops, but all save seven of these were ordered back or left in the streets of Fredericksburg. Late on the morning of the 13th the confused and belated orders began to arrive from Burnside's headquarters across the river; one was for Sumner to assault the Confederate batteries on Marye's Heights. At nightfall Sumner's men retired into Fredericksburg, leaving 4,800 dead or wounded on the field. "Oh, those men, those men over there! I cannot get them out of my mind!" wailed Burnside in an agony of failure. Yet he was planning almost in the same breath to lead in person his old command, the Ninth Corps, in another futile charge in the morning. On the night of the 14th, better judgment prevailed and the order came to retire across the Rappahannock. [Illustration: NEW LEADERS AND NEW PLANS COPYRIGHT, 1911, PATRIOT PUB. CO.]