Longstreet's corps appeared at Fredericksburg on November 19. Lee ordered it to occupy a range of hills behind the town, reaching from the Rappahannock on its left to marshy Massaponax Creek on its right. When Jackson's men arrived more than a week later, Lee dispatched them as far as 20 miles down river from Fredericksburg. The Confederate army thus guarded a long stretch of the Rappahannock, unsure of where the Federals might attempt a crossing. Burnside harbored the same uncertainties. After agonizing deliberation, he finally decided to build bridges at three places - two opposite the city and the other one a mile downstream. The Union commander knew that Jackson's corps could not assist Longstreet in resisting a river passage near town. Thus, Burnside's superior numbers would encounter only half of Lee's legions. Once across the river, the Federals would strike Longstreet's overmatched defenders, outflank Jackson, and send the whole Confederate army reeling toward Richmond.
Burnside's lieutenants, however, doubted the practicality of their chiefs plan. "There were not two opinions among the subordinate officers as to the rashness of the undertaking, "wrote one corps commander. Nevertheless, in the foggy pre-dawn hours of December 11, Union engineers crept to the riverbank and began laying their pontoons. Skilled workmen from two New York regiments completed a pair of bridges at the lower crossing and pushed the upstream spans more than halfway to the opposite bank; then the sharp crack of musketry erupted from the river-front houses and yards of Fredericksburg.
These shots came from a brigade of Mississippians under William Barksdale . Their job was to delay any Federal attempt to negotiate the Rappahannock at Fredericksburg. Nine distinct and desperate attempts were made to complete the bridge[s] reported a Confederate officer, "but every one was attended by such heavy loss that the efforts were abandoned.."
Burnside now turned to his artillery chief, Brigadier General Henry J. Hunt, and ordered him to blast Fredericksburg into submission with some 150 guns trained on the city from Stafford Heights. Such a barrage would surely dislodge the Confederate infantry and permit completion of the bridges. Shortly after noon, Hunt gave the signal to commence fire. "Rapidly the huge guns vomited forth their terrible shot and shell into every corner and thoroughfare of [Fredericksburg]," remembered an eyewitness.
The bombardment continued for nearly two hours, during which 8,000 projectiles rained destruction on Fredericksburg. Then the grand cannonade ceased and the engineers ventured warily to the ends of their unfinished bridges. Suddenly -impossibly - muzzles flashed again from the cobble-strewn streets and more pontoniers tumbled into the cold waters of the Rappahannock.
Burnside now authorized volunteers to ferry themselves across the river in the clumsy pontoon boats. Men from Michigan, Massachusetts, and New York scrambled aboard the scows, frantically pulling at oars to navigate the hazardous 400 feet to the Confederates' side. Once on shore, the Federals charged Barksdale's marksmen who, despite orders to fall back, fiercely contested each block in a rare example of street fighting during the Civil War. After dusk the brave Mississippians finally withdrew to their main line, the bridge builders completed their work, and the Army of the Potomac entered Fredericksburg. [See text of a walking tour brochure on this street fighting.]