Seven Days' Battle
Johnston's assault was bungled, but it discouraged McClellan from further offensive action. Erroneously convinced that he was outnumbered by an enemy of 200,000 troops (the actual number was 85,000), McClellan opted to prepare for a siege of Richmond. He also reversed the disposition of his army relative to the Chickahominy, moving all but Fitz John Porter's corps of 30,000 men south of the river. Porter's task was to protect communications across the river and receive McDowell, if and when he should arrive. In the meantime, Confederate Gen. Robert E. Lee replaced Johnston, who had been wounded in battle. Lee faced a situation identical to Johnston's, with McClellan in front and McDowell behind. His solution was likewise similar. Rather than defend against a significantly reinforced enemy, Lee prepared to strike McClellan, hoping to defeat him, and then turn on McDowell. Lee summoned “Stonewall” Jackson, who had been operating in the Shenandoah Valley, to join him. Intelligence informed McClellan that Jackson was en route and headed straight for Porter's corps, yet McClellan did nothing to strengthen his exposed flank.
Lee concentrated 55,000 soldiers against Porter, leaving only 30,000 troops to guard against McClellan's 70,000 men south of the Chickahominy. On 26 May he attacked, driving Porter from his position at Mechanicsville east along the river. Fortunately for McClellan, the Confederate attack was poorly handled and Porter ably defended himself, despite the absence of any help from McClellan. However, Lee's assault threatened McClellan's line of communications, prompting him to shift his base of operations south to the James River.
Again, Lee attempted to destroy Porter on the 27th at Gaines' Mill, with similar disappointing results. Porter was nonetheless obliged to withdraw across the river, which reunited the Army of the Potomac. With the change of base, and with the Chickahominy between him and Lee, McClellan might well have held his ground. But he was convinced that Lee now had 250,000 men (nearly three times Lee's actual strength) and could see only imminent disaster if he stayed put. On the 28th, McClellan began a full‐scale retreat. Bridges over the Chickahominy were burned, as were tons of supplies that could not be carried away, delaying Lee's pursuit one day. The withdrawal was hastily executed and without the benefit of McClellan's personal guidance. He had ridden ahead to Harrison's Landing and failed to appoint a second in command. Only Lee's momentary confusion about McClellan's intentions saved the Union army from immediate attack.
Once apprised that McClellan was moving south, Lee sent two divisions on a circuitous route to strike the Union right, while the rest of Lee's army came down on its rear. Confederate forces caught up with the Union rearguard at Savage's Station on the 29th. Lee's flanking elements failed to appear, and the Federal army escaped.
As the Union retreat continued, a mammoth bottleneck developed at Frayser's Farm, halting the withdrawal. There Lee attempted to concentrate his forces and envelop the Federal line, but again his subordinates were slow, and the Union army escaped. On 1 July, McClellan's force held an impressive defensive position atop Malvern Hill. Frustrated by his previous inability to engage McClellan successfully, Lee ordered an imprudent and costly frontal attack against the closed lines and massed artillery of the Federals.
When the Army of the Potomac reached Harrison's Landing, Lee ended his counteroffensive. During seven days of fighting, the Confederates suffered about 20,500 casualties to the Union's 16,500. Despite the higher casualties, Lee was proclaimed a hero in the South, for he had taken the offensive and driven a larger army away from Richmond. McClellan, believing he had saved his army from a larger force, criticized Washington for not giving him more support.
[See also Civil War: Military and Diplomatic Course.]
Clifford Dowdey , The Seven Days, 1964.
Stephen W. Sears , To the Gates of Richmond: The Peninsular Campaign, 1992.
T. R. Brereton
"Seven Days' Battle." The Oxford Companion to American Military History. . Encyclopedia.com. (August 17, 2018). http://www.encyclopedia.com/history/encyclopedias-almanacs-transcripts-and-maps/seven-days-battle
"Seven Days' Battle." The Oxford Companion to American Military History. . Retrieved August 17, 2018 from Encyclopedia.com: http://www.encyclopedia.com/history/encyclopedias-almanacs-transcripts-and-maps/seven-days-battle