The Peninsula campaign (also known as the Peninsular campaign) of the American Civil War was a major Union operation launched in southeastern Virginia from March to July 1862, the first large-scale offensive in the Eastern Theater. The operation, commanded by Major General George B. McClellan, was an amphibious turning movement against the Confederate States Army in Northern Virginia, intended to capture the Confederate capital of Richmond. Despite the fact that Confederate spy Thomas Nelson Conrad had obtained documents describing McClellan's battle plans from a double agent in the War Department, McClellan was initially successful against the equally cautious General Joseph E. Johnston, but the emergence of the more aggressive General Robert E. Lee turned the subsequent Seven Days Battles into a humiliating Union defeat.
McClellan landed his army at Fort Monroe and moved northwest, up the Virginia Peninsula. Confederate Brigadier General John B. Magruder's defensive position on the Warwick Line caught McClellan by surprise. His hopes for a quick advance foiled, McClellan ordered his army to prepare for a siege of Yorktown. Just before the siege preparations had been completed, the Confederates, now under the direct command of Johnston, began a withdrawal toward Richmond. The first heavy fighting of the campaign occurred during the Battle of Williamsburg in which the Union troops managed some tactical victories, but the Confederates continued their withdrawal. An amphibious flanking movement to Eltham's Landing was ineffective in cutting off the Confederate retreat. During the Battle of Drewry's Bluff, an attempt by the US Navy to reach Richmond by way of the James River was repulsed.
As McClellan's army reached the outskirts of Richmond, a minor battle occurred at Hanover Court House, but it was followed by a surprise attack by Johnston at the Battle of Seven Pines or Fair Oaks. The battle was inconclusive, with heavy casualties, but it had lasting effects on the campaign. Johnston was wounded by a Union artillery shell fragment on May 31 and replaced the next day by the more aggressive Robert E. Lee, who reorganized his army and prepared for offensive action in the final battles of June 25 to July 1, which are popularly known as the Seven Days Battles. The result was that the Union army was unable to enter Richmond, and both armies remained intact.
Background
Military situation
On August 20, 1861, Maj. Gen. George B. McClellan formed the Army of the Potomac, with himself as its first commander. During the summer and fall, McClellan brought a high degree of organization to his new army, and greatly improved its morale by his frequent trips to review and encourage his units. It was a remarkable achievement, in which he came to personify the Army of the Potomac and reaped the adulation of his men. He created defenses for Washington that were almost impregnable, consisting of 48 forts and strong points, with 480 guns manned by 7,200 artillerists.
On November 1, 1861, Gen. Winfield Scott retired and McClellan became general in chief of all the Union armies. The president expressed his concern about the "vast labor" involved in the dual role of army commander and general in chief, but McClellan responded, "I can do it all."
On January 12, 1862, McClellan revealed his intentions to transport the Army of the Potomac by ship to Urbanna, Virginia, on the Rappahannock River, outflanking the Confederate forces near Washington, and proceeding 50 miles (80 km) overland to capture Richmond. On January 27, Lincoln issued an order that required all of his armies to begin offensive operations by February 22, Washington's birthday. On January 31, he issued a supplementary order for the Army of the Potomac to move overland to attack the Confederates at Manassas Junction and Centreville. McClellan immediately replied with a 22-page letter objecting in detail to the president's plan and advocating instead his Urbanna plan, which was the first written instance of the plan's details being presented to the president. Although Lincoln believed his plan was superior, he was relieved that McClellan finally agreed to begin moving, and reluctantly approved. On March 8, doubting McClellan's resolve, Lincoln called a council of war at the White House in which McClellan's subordinates were asked about their confidence in the Urbanna plan. They expressed their confidence to varying degrees. After the meeting, Lincoln issued another order, naming specific officers as corps commanders to report to McClellan (who had been reluctant to do so prior to assessing his division commanders' effectiveness in combat, even though this would have meant his direct supervision of twelve divisions in the field).
Before McClellan could implement his plans, the Confederate forces under General Joseph E. Johnston withdrew from their positions before Washington on March 9, assuming new positions south of the Rappahannock, which completely nullified the Urbanna strategy. McClellan retooled his plan so that his troops would disembark at Fort Monroe, Virginia, and advance up the Virginia Peninsula to Richmond. However, McClellan came under extreme criticism from the press and the Congress when it was found that Johnston's forces had not only slipped away unnoticed, but had for months fooled the Union Army through the use of Quaker Guns.
A further complication for the campaign planning was the emergence of the first Confederate ironclad warship, CSS Virginia, which threw Washington into a panic and made naval support operations on the James River seem problematic. In the Battle of Hampton Roads (March 8–9, 1862), Virginia defeated wooden U.S. Navy ships blockading the harbor of Hampton Roads, Virginia, including the frigates USS Cumberland and USS Congress on March 8, calling into question the viability of any of the wooden ships in the world. The following day, the USS Monitor ironclad arrived at the scene and engaged with the Virginia, the famous first duel of the ironclads. The battle, although inconclusive, received worldwide publicity. After the battle, it was clear that ironclad ships were the future of naval warfare. Neither ship severely damaged the other; the only net result was keeping Virginia from attacking any more wooden ships.
On March 11, 1862, Lincoln removed McClellan as general-in-chief, leaving him in command of only the Army of the Potomac, ostensibly so that McClellan would be free to devote all his attention to the move on Richmond. Although McClellan was assuaged by supportive comments Lincoln made to him, in time he saw the change of command very differently, describing it as a part of an intrigue "to secure the failure of the approaching campaign."
Opposing forces
Union
The Army of the Potomac had approximately 50,000 men at Fort Monroe when McClellan arrived in late March, but this number grew to 121,500 before hostilities began. The army was organized into three corps and other units, as follows:
- II Corps, Brig. Gen. Edwin V. Sumner commanding: divisions of Brig. Gens. Israel B. Richardson and John Sedgwick
- III Corps, Brig. Gen. Samuel P. Heintzelman commanding: divisions of Brig. Gens. Fitz John Porter, Joseph Hooker, and Charles S. Hamilton
- IV Corps, Brig. Gen. Erasmus D. Keyes commanding: divisions of Brig. Gens. Darius N. Couch, William F. "Baldy" Smith, and Silas Casey
- 1st Division of the I Corps, Brig. Gen. William B. Franklin commanding
- Reserve infantry commanded by Brig. Gen. George Sykes
- Cavalry commanded by Brig. Gen. George Stoneman
- The garrison of Fort Monroe, 12,000 men under Maj. Gen. John E. Wool; Wool was quickly transferred to another department for duty in Baltimore after the War Department realized that he technically outranked McClellan.
Confederate
On the Confederate side, Johnston's Army of Northern Virginia (newly named as of March 14) was organized into three wings, each composed of several brigades, as follows:
- Left Wing, Maj. Gen. D. H. Hill commanding: brigades of Brig. Gen. Robert E. Rodes, Winfield S. Featherston, Jubal A. Early, and Gabriel J. Raines
- Center Wing, Maj. Gen. James Longstreet commanding: brigades of Brig. Gens. A. P. Hill, Richard H. Anderson, George E. Pickett, Cadmus M. Wilcox, Raleigh E. Colston, and Roger A. Pryor
- Right Wing, Maj. Gen. John B. Magruder commanding: division of Brig. Gen. Lafayette McLaws (brigades of Brig. Gens. Paul J. Semmes, Richard Griffith, Joseph B. Kershaw, and Howell Cobb) and division of Brig. Gen. David R. Jones (brigades of Brig. Gens. Robert A. Toombs and George T. Anderson)
- Reserve force commanded by Maj. Gen. Gustavus W. Smith
- Cavalry commanded by Brig. Gen. J. E. B. Stuart
However, at the time the Army of the Potomac arrived, only Magruder's 11,000 men faced them on the Peninsula. The bulk of Johnston's force (43,000 men) were at Culpeper, 6,000 under Maj. Gen. Theophilus H. Holmes at Fredericksburg, and 9,000 under Maj. Gen. Benjamin Huger at Norfolk. In Richmond, General Robert E. Lee had returned from work on coastal fortifications in the Carolinas and on March 13 became the chief military adviser to Confederate President Jefferson Davis.
Forces in the Shenandoah Valley played an indirect role in the campaign. Approximately 50,000 men under Maj. Gens. Nathaniel P. Banks and Irvin McDowell were engaged chasing a much smaller force under Stonewall Jackson in the Valley Campaign. Jackson's expert maneuvering and tactical success in small battles kept the Union men from reinforcing McClellan, much to his dismay. He had planned to have 30,000 under McDowell to join him.
Magruder had prepared three defensive lines across the Peninsula. The first, about 12 miles (19 km) north of Fort Monroe, contained infantry outposts and artillery redoubts, but was insufficiently manned to prevent any Union advance. Its primary purpose was to shield information from the Union about a second line extending from Yorktown to Mulberry Island. This Warwick Line consisted of redoubts, rifle pits, and fortifications behind the Warwick River. By enlarging two dams on the river, the river was turned into a significant military obstacle in its own right. The third defensive line was a series of forts at Williamsburg, which waited unmanned for use by the army if it had to fall back from Yorktown.
Initial movements
Movement to the Peninsula and the siege of Yorktown
Confederate
Union
McClellan's army began to sail from Alexandria on March 17. It was an armada that dwarfed all previous American expeditions, transporting 121,500 men, 44 artillery batteries, 1,150 wagons, over 15,000 horses, and tons of equipment and supplies. An English observer remarked that it was the "stride of a giant."
With the Virginia still in operation, the U.S. Navy could not assure McClellan that they could protect operations on either the James or the York, so his plan of amphibiously enveloping Yorktown was abandoned, and he ordered an advance up the Peninsula to begin April 4.
On April 5, the IV Corps of Brig. Gen. Erasmus D. Keyes made initial contact with Confederate defensive works at Lee's Mill, an area McClellan expected to move through without resistance. Magruder, a fan of theatrics, set up a successful deception campaign. By moving one company in circles through a glen, he gained the appearance of an endless line of reinforcements marching to relieve him. He also spread his artillery very far apart and had it fire sporadically at the Union lines. Federals were convinced that his works were strongly held, reporting that an army of 100,000 was in their path. As the two armies fought an artillery duel, reconnaissance indicated to Keyes the strength and breadth of the Confederate fortifications, and he advised McClellan against assaulting them. McClellan ordered the construction of siege fortifications and brought his heavy siege guns to the front. In the meantime, Gen. Johnston brought reinforcements for Magruder.
McClellan chose not to attack without more reconnaissance and ordered his army to entrench in works parallel to Magruder's and besiege Yorktown. McClellan reacted to Keyes's report, as well as to reports of enemy strength near the town of Yorktown, but he also received word that the I Corps, under Maj. Gen. Irvin McDowell, would be withheld for the defense of Washington, instead of joining him on the Peninsula as McClellan had planned. In addition to the pressure of Jackson's Valley campaign, President Lincoln believed that McClellan had left insufficient force to guard Washington and that the general had been deceptive in his reporting of unit strengths, counting troops as ready to defend Washington when they were actually deployed elsewhere. McClellan protested that he was being forced to lead a major campaign without his promised resources, but he moved ahead anyway. For the next 10 days, McClellan's men dug while Magruder steadily received reinforcements. By mid April, Magruder commanded 35,000 men, barely enough to defend his line.
Although McClellan doubted his numeric superiority over the enemy, he had no doubts about the superiority of his artillery. The siege preparations at Yorktown consisted of 15 batteries with more than 70 heavy guns. When fired in unison, these batteries would deliver over 7,000 pounds of ordnance onto the enemy positions with each volley.
On April 16, Union forces probed a point in the Confederate line at Dam No. 1, on the Warwick River near Lee's Mill. Magruder realized the weakness of his position and ordered it strengthened. Three regiments under Brig. Gen. Howell Cobb, with six other regiments nearby, were improving their position on the west bank of the river overlooking the dam. McClellan became concerned that this strengthening might impede his installation of siege batteries. He ordered Brig. Gen. William F. "Baldy" Smith, a division commander in the IV Corps, to "hamper the enemy" in completing their defensive works.