Church bells in Fredericksburg tolled 3 a.m. on December 11, 1862, as Union engineers wrestled pontoon boats toward the river's edge. They intended to use the boats to construct two of the six floating bridges that the Army of the Potomac would need to cross the Rappahannock. For two hours the engineers toiled in darkness, trying to complete the spans before Confederate sharpshooters on the opposite bank spotted them.
At 5 a.m. Confederate musket fire burst from cellars and windows across the river. Those engineers not shot down scrambled for cover on the shore. Union cannon atop Stafford Heights responded with an eight-hour-long bombardment that ravaged the city but failed to silence the Confederates. Only by ferrying troops across the river under fire was the Union army able to drive the Confederates from the town and complete the bridges.