Gen. Robert E. Lee assumed command of the Army of Northern Virginia on June 1. For the next 2 weeks, in the shadow of the capital of the Confederacy, Richmond, Virginia, his men dug field fortifications to strengthen the capital's defenses. To the east, across the fields and bootomlands, lay Maj. Gen. George B. McClellan's huge Army of the Potomac. While the Confederates spaded, the Federals dragged up heavy artillery to blast the defenders out of their capital. Lee, though outnumbered, decided to seize the initiative and attack McClellan before he could bring his ordnance to bear.
The position of the Union army gave the Confederate commander the opportunity to undertake an offensive. McClellan, after the battle of Seven Pines, had moved the bulk of the army, some 70,000-men strong, south of Chickahominy River, while keeping Maj. Gen. Fitz John Porter's reinforced V Corps, about 30,000-man strong, north of the stream. McCleelan maintained this deployment in the expectation of an overland advance from Fredericksburg, Virginia by Maj. Gen. Irvin McDowell's corps.
On the 12th, Lee dispatched Brig. Gen. J.E.B. Stuart and the cavalry on a reconnaissance to locate McClellan's exact position. The dashing Stuart boldly encircled the Union army in a 3-day ride, seizing prisoners and destroying supplies. Stuart reported to Lee that the Union army's right flank was vunerable to an attack.
Lee fashioned a bold plan. Leaving only 25,000 men south of the river to confront McClellan's 70,000, Lee prepared to strike Porter with 47,000 men. To deceive the Federals, he sent 1 division westward to the Shenandoah Valley, while at the same time recalling Maj. Gen. Thomas J. "Stonewall" Jackson and his 18,000 troops from the valley to a point north of Porter's unsupported right flank. Jackson, riding ahead of his men, conferred with Lee and other generals. The Confederate officers scheduled the offensive for June 26th.
McClellan, meanwhile, completed the necessary preliminaries for his long-promised assault on Richmond. Cautious by temperament, he believed his miserable intelligence, which reported that the Confederates outnumbered him 2-to-1. On the 25th, the day before Lee's scheduled advance, McClellan ordered a reconnaissance in force south of the Chickahominy. The Confederate defenders met the Federals at Oak Grove in a brief, lively engagement. The Seven Days Campaign had begun.
On the 26th, Lee seized the initiative, launching his offensive across the Chickahominy. Three Confederate divisions, those of Maj. Gens. Ambrose P. Hill, Daniel H. Hill, and James Longstreet, sat poised to strike, awaiting the arrival of Jackson from the north. Jackson, however, never reached the field on this day, and his strange performance throughout the campaign seriously hampered the Confederate operations. His failures have been attributated, most persuasively, to lethargy and exhuastion from his Shenandoah Valley campaign and several near-sleepless nights.
A.P. Hill, an impetuous officer, waited for Jackson until mid-afternoon, then crossed the river at Meadow Bridge, and assaulted Porter's troops. The Federals, aligned behind Beaver Dam Creek in a strong position, wrecked Hill's charging brigades with rifle and artillery fire. D.H. Hill brought up some of his brigades, but they fared no better against the entrenched Federals. Porter withdrew after dark to another prepared position behind Boatswain Swamp, near Gaines' Mill. This Battle of Mechanicsville cost the Confederates 1,484 casualties to porter's 361.
Lee, with most of his army now away from Richmond, had to strike Porter again on the 27th. By late morning, the leading Confederates found Porter waiting at Gaines' Mill. The Union corps commander, under orders from McClellan to hold his position at any cost, maintained a strong semicircle defense. Lee's divisions, in mid-afternoon, launched a series of attacks. The stalwart defenders, clinging to the bluff, repulsed them with heavy losses. Finally, at dark, 2 Confederate brigades pierced the Union center and Porter withdrew. This Battle at Gaines' Mill, costing both sides more than 15,000 men, bought for McClellan a crucial day.
McClellan, surprised by Lee's boldness, had become a beaten man, ordering a change of base from the York River to the James River. McClellan described it as a strategic withdrawal, while others, less generous, called it a "great skedaddle". Once Lee took the initiative on the 26th, he never relinquished it during the campaign.
for the next 3 days, the 28- July 1, Lee endeavored to destroy in detail McClellan's retreating army, with its ponderous wagon train and cattle herd. His complicated plan miscarried, however, plauged by faulty staff work and lack of coordination between the attacking divisions. At Allen's Farm, on the 29th, and at White Oak Swamp on the 30th, the Union rearguard repulsed the Confederate thrusts. McClellan halted at a strong position on Malvern Hill, where on July 1, Lee ordered a final attack in an effort to crush the Federals. Union artillry erased the Confederate charges in shellfire and canister.
Lee's bloody defeat on the 1st concluded the campaign. His casualties for the week were an appalling 3,286 killed, 15,909 wounded, and 946 missing, for a total of 20,141. The Federals, on the defensive, suffered 1,734 killed, 8,062 wounded, and 6,053 missing, for a total of 15,849.
The Seven Days Campaign changed the course of the war in Virginia. Lee had relieved the Confederate capital and had seized the initiative in the East, which he maintained until the Battle of Antietam in September. Lee corrected problems plauging his army during their initial campaign together by strengthening his staff, relieving some generals, and grouping his divisions into 2 corps under Londstreet and Jackson. Within weeks, the reorganized Army of Northern Virginia turned north toward a new opponent. McClellan remained on the James River, blaming the Union administration for his defeat and asking for more reinforcements.
McClellan's campaign to capture Richmond was soundly planned but poorly executed, due largely to his inability to make the transition from trainer and organizer to field commander. In the office, as the leader and administrator of a training army, he was excelled. His grasp of strategy was execellent. But in the field, he was cautious to the point of paralysis and slow to the point of lethargy. Unwilling to risk the magnificent military machine he built to losses in combat, he hoped somehow its mere presence before Richmond would cause the Confederacy to collapse. Superior in numbers and equipment at the onset of the campaign, his army had the opportunity to overwhelm the Confederates at any time. Yet by moving slowly, he surrendered the initiative to his opponent. He essentially chose to support an offensive strategy with a tactical defensive. In doing so, he gave himself up to Lee's bold offensive plans.