The Army of the Potomac Mobilizes

General-in-Chief Henry W. Halleck returned to Washington on November 14 after a conference with Major General Ambrose E. Burnside, new commander of the Federal Army of the Potomac. Both Halleck and President Abraham Lincoln had favored a plan of attack based on the army moving southwest along the Orange & Alexandria Railroad to attack General Robert E. Lee’s divided Confederate Army of Northern Virginia at Culpeper Court House. Burnside instead proposed moving southeast down the Rappahannock River to get around Lee’s right flank at Fredericksburg, from which the Federals would have a clear path to the Confederate capital of Richmond.

Lincoln still liked the more direct approach to Lee at Culpeper, but he also liked Burnside’s idea of keeping Washington protected as he moved. The president’s main objection was that Burnside’s ultimate goal was the capture of Richmond and not the destruction of Lee’s army. Ultimately, Halleck notified Burnside that Lincoln had approved his new plan: “The President has just assented to your plan. He thinks that it will succeed, if you move very rapidly; otherwise not.”

Lincoln still had doubts, but he appreciated Burnside’s eagerness to take the offensive so quickly, and he did not want to cause animosity by rejecting the general’s strategy so soon after taking command. Lincoln also approved Burnside’s proposal to group six of the seven army corps into three Grand Divisions. Burnside immediately reorganized the Army of the Potomac, with Major Generals Edwin V. Sumner, Joseph Hooker, and William B. Franklin commanding the Right, Center, and Left Grand Divisions respectively. The forces were concentrated at Warrenton.

Maj Gen A.E. Burnside | Image Credit:

Burnside had already put in an order for pontoon bridges, which he would need to cross the Rappahannock at Falmouth to get to Fredericksburg. Halleck had sent the order to Brigadier General Daniel P. Woodbury, who supervised pontoon materials and distribution for the army from Washington. Halleck believed that Burnside’s plan entailed crossing the Rappahannock above Falmouth and then marching down the south bank to Fredericksburg. Since this would not involve pontoons, Halleck did not mention to Woodbury that the order needed to be rushed.

The first load of pontoons arrived at the capital from Harpers Ferry on the night of the 14th. The remaining pontoons were set to arrive by the 17th, and then they would all be shipped to Burnside’s projected base at Belle Plain. Woodbury planned to send the pontoons overland by wagon train rather than the quicker route by water. He informed Halleck that the overland trip would take five days and claimed that “no one informed me that the success of any important movement depended in the slightest degree upon a pontoon train to leave Washington by land.”

Meanwhile, Lee’s Confederate army remained divided between Lieutenant General James Longstreet’s corps at Culpeper Court House and Lieutenant General Thomas J. “Stonewall” Jackson’s corps at Winchester in the Shenandoah Valley. Lee knew the Federals had advanced to Warrenton and then stopped. After learning of the Federal cavalry raid on Fredericksburg, he began to suspect that the enemy would target that town. Lee had no specific intelligence on this, but the simple fact that the Federals had stopped moving south made him think that the new commander would have a new strategy.

Gen Robert E. Lee | Image Credit:

Lee told Jackson to be ready to hurry east if needed. He sent reinforcements to the Confederate garrison at Fredericksburg and told them to stay on alert. He then directed “the railroad from Fredericksburg to Aquia Creek to be entirely destroyed; the bridges, culverts, &c, to be broken; the cross-ties piled and fired, with the rails piled on top, so as to prevent their future use.”

In a letter to Secretary of War George W. Randolph, Lee proposed destroying the railroad from Fredericksburg to Hanover Junction, along with the Orange & Alexandria Railroad from Gordonsville to the Rappahannock. Lee acknowledged that he was merely acting on a hunch, and, “Were I certain of the route he will pursue, I should commence immediately to make it as difficult as possible.”

Burnside began moving the Potomac army out of Warrenton on the 15th, less than a week after taking command. They were to feint on Culpeper before quickly turning southeast and driving on Falmouth. An officer in the 20th Massachusetts wrote, “I think the Army has got over the depression caused by McClellan’s removal and it is in good heart for anything, but in case of serious reverse, there would be a great want of confidence.” Men of the 24th New Jersey sang a new song to the tune of “John Brown’s Body”:

“We’ll soon light our fires on the Rappahannock shore;
“We’ll soon light our fires on the Rappahannock shore;
“And tell Father Abraham he needn’t call for more;
“While we go marching on…”

The Federals took up the practice begun by John Pope’s Army of Virginia in July of looting and pillaging as they marched. A Massachusetts soldier wrote, “We have had a grand time, killing and eating their sheep, cattle and poultry. One farmer here lost nearly three hundred sheep the first night our boys encamped.” While Unionists were to be protected, “Our officers say nothing if we take a rebel’s turkeys, hens, or sheep to eat; they like their share.”

The sudden swiftness of the Federal army after having been so sluggish for so long under George B. McClellan stunned the Confederates. Federal cavalry seized the bridge at Rappahannock Station before the enemy could destroy it, and Federal artillery began shelling Confederate positions at Culpeper. This confused Lee, who thought that Burnside would target Fredericksburg; he did not yet know that the Federal “attack” was part of Burnside’s feint.

By evening, the Federals had disengaged and Lee figured out what was happening. He notified Colonel William Ball, commanding the Confederate defenses at Fredericksburg, “It is reported that the enemy is moving from Warrenton today, and it is probable that he is marching upon Fredericksburg.” Lee then dispatched cavalry to Fredericksburg. The troopers were to defend the town if Federals had not captured it already. If the town was captured, the Confederates were to “take position on the Fredericksburg and Richmond Railroad, where it crosses the North Anna.”

Lee instructed Ball, “The bridges and culverts must be thoroughly destroyed,” with the cross-ties “removed and piled, with the rails placed across them, and, when the timber is sufficiently dry, fired; the weight of the bars will thus cause them to bend, and prevent their being relaid.” Lee then awaited Burnside’s next move.

Meanwhile, Burnside sent a staff officer to inquire about the pontoons. They had all arrived at Washington by the 15th. Woodbury was now aware of the rush, but he was not sure which route was the quickest. He therefore instructed Major Ira Spaulding of the 50th New York Engineers to send them in two trips, one by water and one by land. The water route to Belle Plain would turn out to be the quickest, but Woodbury was not informed that once the pontoons arrived, they would need to be transported overland to the Rappahannock. Thus, no arrangements were made to have wagons ready to haul them away.


  • Angle, Paul M., A Pictorial History of the Civil War Years. New York: Doubleday, 1967.
  • Catton, Bruce, The Army of the Potomac: Mr. Lincoln’s Army. Garden City, NY: Doubleday & Co., Inc., 1951.
  • Catton, Bruce, The Army of the Potomac: Glory Road. Garden City, NY: Doubleday & Co., Inc., 1952.
  • Foote, Shelby, The Civil War, A Narrative: Fort Sumter to Perryville. New York: Vintage Books, 1958.
  • Goolrick, William K., Rebels Resurgent: Fredericksburg to Chancellorsville. Alexandria, VA: Time-Life Books, 1983.
  • Long, E.B. with Long, Barbara, The Civil War Day by Day. New York: Da Capo Press, Inc., 1971.
  • Longstreet, James, From Manassas to Appomattox: Memoirs of the Civil War in America. Philadelphia: J.B. Lippincott Co. (Kindle Edition), 1895.
  • Sears, Stephen W., Lincoln’s Lieutenants: The High Command of the Army of the Potomac. Boston, New York: Houghton Mifflin Harcourt Books, (Kindle Edition), 2017.
  • Wert, Jeffry D. (Patricia L. Faust ed.), Historical Times Illustrated Encyclopedia of the Civil War. New York: Harper & Row, 1986.

Leave a Reply