March 17, 1862 – Major General George B. McClellan finally mobilized the Army of the Potomac to begin his grand offensive to destroy the Confederacy.
The Confederate withdrawal from northern Virginia blocked McClellan’s proposed army landing at Urbanna. However, with the U.S.S. Monitor now controlling the Hampton Roads area, McClellan planned to move his army further south down Virginia’s coast to land at Fort Monroe, on the Peninsula between the York and James rivers. As news of this planned landing reached Richmond, panic spread among the residents. General John H. Winder, the city’s provost marshal, relocated the passport office to accommodate the rush of people trying to leave town.
On March 13, McClellan met with his four new corps commanders at Fairfax Court House and shared his plan for landing the Army of the Potomac on the Peninsula. Fort Monroe, three miles across Hampton Roads from Confederate-held Norfolk, would be the Federals’ supply base. McClellan asserted that not only would a march from Fort Monroe to Richmond be 10 miles shorter than one from Manassas Junction to the same place, but the Peninsula roads were usable any time of year. Even better, the navy could support the advance from the York River.
McClellan spent the next day planning to withdraw his army to Alexandria and divide it into corps in accordance with Lincoln’s order to create a corps structure. The five new army corps were to be commanded by Major Generals McDowell, Edwin V. Sumner, Samuel P. Heintzelman, Erasmus D. Keyes, and Nathaniel P. Banks (currently stationed in the Shenandoah Valley). Lincoln had selected these corps commanders to better enable McClellan to lead overall army operations.
By the 17th, McClellan was finally ready to “give the death-blow to the rebellion that has distracted our once happy country.” It had taken over seven months, but he had forged an army “magnificent in material, admirable in discipline and instruction, excellently equipped and armed.” The men marched through Alexandria and boarded transports that would take them down the Potomac River, into Chesapeake Bay, and on to Fort Monroe. This would outflank the Confederates on the Rappahannock River and put the army on a lightly defended path leading northwest to Richmond.
The largest army ever assembled in North America embarked on the largest amphibious operation ever attempted in the Western Hemisphere. In an incredible display of logistical prowess, Quartermaster General Montgomery Meigs assembled 113 steamers, 188 schooners, and 88 barges to transport 121,500 officers and men, 44 artillery batteries bearing 300 guns, 14,592 animals, 1,150 wagons, 74 ambulances, pontoon bridges, telegraph wire, and enormous quantities of supplies and equipment. This effort was supported by a state-of-the-art navy.
The 200-mile transfer to Fort Monroe began one day ahead of Lincoln’s deadline and was scheduled to take three weeks. McClellan moved the troops by division, which some saw as a disregard for Lincoln’s corps structure. In a last minute change, McClellan moved the divisions of McDowell’s corps from first to last in the order of embarkation. This decision later proved fateful.