Editing Seven Days Battles (section)

==Background==

===Military situation===
{{Main|Eastern Theater of the American Civil War}}
{{further|American Civil War}}

===The Peninsula campaign===
{{Main|Peninsula campaign}}
[[File:Peninsula Campaign March-May 1862.png|thumb|upright=1.5|Map of events during the Peninsula campaign to the [[Battle of Seven Pines]]
{{legend|#ff0000|Confederate}}
{{legend|#0000ff|Union}}
]]

The [[Peninsula campaign]] was the unsuccessful attempt by McClellan to capture the [[Confederate States of America|Confederate]] capital of Richmond and end the war. It started in March 1862, when McClellan landed his army at [[Fort Monroe]] and moved northwest, up the [[Virginia Peninsula]] beginning in early April. Confederate [[Brigadier General (CSA)|Brig. Gen.]] [[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 [[Battle of Yorktown (1862)|siege of Yorktown]]. Just before the siege preparations were completed, the Confederates, now under the direct command of [[Joseph E. Johnston|Johnston]], began a withdrawal toward Richmond.<ref name="Sears, pp. 8">Sears, ''Gates of Richmond'', p. xi; Miller, pp. 8–18; Burton, ''Peninsula & Seven Days'', p. 5; Eicher, pp. 268–74.</ref>

The first heavy fighting of the campaign occurred in the [[Battle of Williamsburg]] (May 5), in which the Union troops managed some tactical victories, but the Confederates continued their withdrawal. An amphibious flanking movement to [[Battle of Eltham's Landing|Eltham's Landing]] (May 7) was ineffective in cutting off the Confederate retreat. In the [[Battle of Drewry's Bluff]] (May 15), an attempt by the [[United States Navy]] to reach Richmond by way of the James River was repulsed.<ref name="Sears, pp. 8"/>

As McClellan's army reached the outskirts of Richmond, a minor battle occurred at [[Battle of Hanover Court House|Hanover Court House]] (May 27), but it was followed by a surprise attack by Johnston at the [[Battle of Seven Pines]] or Fair Oaks on May 31 and June 1. The battle was inconclusive, with heavy casualties, but it had lasting effects on the campaign. Johnston was wounded and replaced on June 1 by the more aggressive Robert E. Lee. Lee spent almost a month extending his defensive lines and organizing his [[Army of Northern Virginia]]; McClellan accommodated this by sitting passively to his front, waiting for dry weather and roads, until the start of the Seven Days.<ref name="Rafuse, p pp. 20">Rafuse, p. 220; Miller, pp. 20–25; Burton, ''Extraordinary Circumstances'', p. 26; Eicher, pp. 275–80.</ref> Lee, who had developed a reputation for caution early in the war, knew he had no numerical superiority over McClellan, but he planned an offensive campaign that was the first indication of the aggressive nature he would display for the remainder of the war.<ref name="Rafuse, p pp. 20"/>

===Planning for offensives===
Lee's initial attack plan, similar to Johnston's plan at Seven Pines, was complex and required expert coordination and execution by all of his subordinates, but Lee knew that he could not win in a battle of attrition or siege against the Union Army. It was developed at a meeting on June 23. The Union Army straddled the rain-swollen [[Chickahominy River]], with the bulk of the army, four corps, arrayed in a semicircular line south of the river. The remainder, the V Corps under Brig. Gen. [[Fitz John Porter]], was north of the river near [[Mechanicsville, Hanover County, Virginia|Mechanicsville]] in an L-shaped line facing north–south behind Beaver Dam Creek and southeast along the Chickahominy. Lee's plan was to cross the Chickahominy with the bulk of his army to attack the Union north flank, leaving only two divisions (under Maj. Gens. [[Benjamin Huger (general)|Benjamin Huger]] and [[John B. Magruder]]) to hold a line of entrenchments against McClellan's superior strength. This would concentrate about 65,500 troops to oppose 30,000, leaving only 25,000 to protect Richmond and to contain the other 60,000 men of the Union Army. The Confederate cavalry under Brig. Gen. [[J.E.B. Stuart]] had reconnoitered Porter's right flank—as part of a daring but militarily dubious circumnavigation of the entire Union Army from June 12 to 15—and found it vulnerable.<ref>Esposito, text to map 45 (called Stuart's raid "of dubious value"); Time-Life, p. 25–30; Rafuse, p. 221; Harsh, pp. 80–81; Burton, ''Extraordinary Circumstances'', pp. 18–23; Sears, ''Gates of Richmond'', pp. 195–97; Eicher, pp. 282–83.</ref>

Lee intended for Jackson to attack Porter's right flank early on the morning of June 26, and A.P. Hill would move from Meadow Bridge to Beaver Dam Creek, which flows into the Chickahominy, advancing on the Federal trenches. (Lee hoped that Porter would evacuate his trenches under pressure, obviating the need for a direct frontal assault.) Following this, Longstreet and D.H. Hill would pass through Mechanicsville and join the battle. Huger and Magruder would provide diversions on their fronts to distract McClellan as to Lee's real intentions. Lee hoped that Porter would be overwhelmed from two sides by the mass of 65,000 men, and the two leading Confederate divisions would move on Cold Harbor and cut McClellan's communications with White House Landing.<ref>Eicher, p. 283; Time-Life, p. 31; Rafuse, p. 221.</ref>

McClellan also planned an offensive. He had received intelligence that Lee was prepared to move and that the arrival of Maj. Gen. [[Stonewall Jackson|Thomas J. "Stonewall" Jackson's]] force from the [[Valley campaign|Shenandoah Valley]] was imminent (McClellan was aware of Jackson's presence at Ashland Station, but did nothing to reinforce Porter's vulnerable corps north of the river).<ref>Salmon, pp. 96–97.</ref> He decided to resume the offensive before Lee could. Anticipating Jackson's reinforcements marching from the north, he increased cavalry patrols on likely avenues of approach. He wanted to advance his siege artillery about a mile and a half closer to the city by taking the high ground on Nine Mile Road around Old Tavern. In preparation for that, he planned an attack on Oak Grove, south of Old Tavern and the [[Richmond and York River Railroad]], which would position his men to attack Old Tavern from two directions.<ref>Sears, ''Gates of Richmond'', p. 183; Esposito, map 44; Time-Life, p. 31; Burton, ''Extraordinary Circumstances'', pp. 41–43; Salmon, p. 97.</ref>