The Pontoon Bridges at the Battle of Fredericksburg

In November 1862, President Abraham Lincoln promoted Major General Ambrose Burnside to commander of the Army of the Potomac, replacing Major General George McClellan.  Burnside developed a plan to capture the Confederate capitol of Richmond, Virginia.  He proposed to march his army to the vicinity of Falmouth, Virginia, across the Rappahannock River from Fredericksburg.  He would cross the river on pontoon bridges and then drive on to Richmond.  Burnside believed that a rapid movement of his army would catch the Army of Northern Virginia and its commander, General Robert E. Lee, off guard, and that the river crossing could be made before Lee could concentrate his forces at Fredericksburg and contest the crossing.

Although he had reservations about it, Lincoln approved the plan on November 14th.  Burnside went into action immediately.  On November 15th, he began to pull his army out of the Warrenton, Virginia area and head southeast towards Fredericksburg.  Lee began a pullback from his position in front of the Army of the Potomac.  Unsure of the Federals’ destination, Lee had to hold back and see how the situation developed before he could make a countermove.  The Union Army began arriving in force at Falmouth on November 17th.

The first important step in the campaign had been successfully executed; Burnside’s army had made it to Fredericksburg ahead of Lee.  The next step was to get the army across  the Rappahannock River and push on to Richmond.  However, the pontoon bridges and bridging materials had not arrived.  In fact, they were just leaving Washington.

Transporting the Pontoons to Fredericksburg

Before embarking on the campaign, Burnside had arranged for the shipment of the pontoon wagon trains through the Union Army’s General in Chief, Henry Halleck.  But neither Halleck nor Quartermaster General Montgomery Meigs, who was responsible for supplying necessary equipment and supplies for the pontoon trains, acted with the urgency needed.  The 50th New York Engineers left Washington with one of two pontoon trains on November 19th, traveling overland to Falmouth.

Heavy rains turned the roads to mud and slowed progress.  A second pontoon train had been sent down the Potomac River to the town of Aquia Landing; from there, the train would travel overland the last few miles.  With the roads impassable due to the mud, the overland train was diverted to the Potomac River, the pontoon boats were formed into rafts, and towed downriver to Aquia Landing.  The engineers and equipment did not arrive at Falmouth until November 25th.  By this time Lee’s army was arriving, and the opportunity to cross the Rappahannock River uncontested was gone.

Burnside considered his options, including the possibility of crossing the Rappahannock at another location.  In the end, he concluded that crossing at Fredericksburg was his best bet.  The pontoon bridges would be placed on December 11th.

Constructing the Bridges

On the night of December 10th, the 15th New York Engineers and the U.S. Regular Engineer Battalion quietly moved to a position about a mile downriver from Fredericksburg.  The engineers built two bridges at this site, facing little opposition.   When the bridges were nearly complete, a small Confederate force charged the engineers and inflicted some casualties, but Union artillery fire drove the attackers away.  The two bridges were finished by 11:00 A.M.

The 50th New York Engineers were charged with the task of building bridges in two locations; one at the southern end of town and two at the northern end.  Work commenced about 3:00 A.M.  On the opposite shore, Brigadier General William Barksdale alerted his commander, Major General Lafayette McLaws, that Federal bridge building had commenced.  McLaws instructed Barksdale to allow the construction to continue until the engineers were within close range.  Barksdale moved his brigade, consisting of the 13th, 17th, 18th, and 21st Mississippi Infantry regiments, along with some reinforcements from the 8th Florida Infantry into position along the river.  The men took cover in buildings, behind fences, and in rifle pits.  Shortly after 5:00 A.M., the Confederates opened fire on the engineers working on the bridges and on the opposite riverbank.

The Confederate musket fire killed one officer and two enlisted men on the northern bridge site, and wounded several others.  The unarmed engineers ran for the shore and took cover as the enemy fire raked the Federal positions.

Brigadier General Henry Hunt, the Army of the Potomac’s Chief of Artillery, had placed his batteries on Stafford Heights, east of the town.  The artillery began firing at the Confederate positions in Fredericksburg.  After considerable bombardment, the cannonade stopped and the engineers attempted to resume their work, only to be hit by more Confederate fire and again driven back.  The artillery resumed blasting Fredericksburg, and when the firing eased, the engineers again tried to resume work, and were again driven back by Barksdale’s determined riflemen.  Union infantry across the river also exchanged fire with the Mississippians .

This continued well into the afternoon.  To break the stalemate, General Hunt suggested to Burnside that infantrymen be sent across the river in boats to secure the area and drive out the enemy.  Burnside agreed to the idea if Hunt would find volunteers for the risky venture.

Assault on the Town

Colonel Norman J. Hall, commanding one of the Union Second Corps brigades, volunteered his 7th Michigan Infantry for the task.   They would cross near the northern bridge site, and the 19th Massachusetts Infantry would cross over after the 7th Michigan.

As the infantry prepared to cross, Hunt’s artillery opened up one more time in an attempt to clear out some of the resistance.  After a half hour, the bombardment ended, and the 7th Michigan began to cross the Rappahannock in boats with 20 to 25 men in each boat.  The Confederate defenders fired on the boats, killing and wounding some of the Michigan men.  But they pressed on, rowing as hard as they could, and reached the Fredericksburg shore.  The 7th Michigan jumped out of the boats, scrambled up and over the riverbank, and engaged the Confederates in house to house fighting.  Within a few minutes, the 7th Michigan captured 30 prisoners and drove Barksdale’s Mississippians back from the river.  The 19th Massachusetts then crossed over and assisted the 7th Michigan in the deadly fighting in the streets.  But the bridgehead on the Fredericksburg side of the river was secure, and work resumed on the bridges.  With their work on the bridge south of town complete, the 15th New York Engineers helped complete the other bridges.

This was the first time in the history of the U.S. Military that a water crossing was made and a beachhead successfully established.  More Union troops crossed the bridges into town and assisted in clearing out the stubborn resistance. Fighting continued in the streets of Fredericksburg all day, before Barksdale withdrew.  He had successfully accomplished his mission to delay the Federal advance and allow Lee time to prepare his defense.  With the late arrival and deployment of the pontoon bridges, Ambrose Burnside’s Fredericksburg Campaign was doomed to failure. On the night of December 15th, the Union Army withdrew back across the Rappahannock River on these pontoon bridges after suffering a crushing defeat at the Battle of Fredericksburg.

Sources:

“The Confederate Left at Fredericksburg”, by Lafayette McLaws.  In Battles and Leaders of the Civil War, Volume III.  Clarence C. Buel and Robert U. Johnson, Eds. 1887-8. Reprint. Secaucus, NJ: Castle.

The Fredericksburg Campaign: Winter War on the Rappahannock
by Francis A. O’Reilly.  Baton Rouge, Louisiana:  Louisiana State University Press, 2003.

Official Records of the Union and Confederate Armies in the War of the Rebellion.  Series I, Volume XXI.  U. S War Department, Washington DC, 1880-1901.