Seven Days Battles - Planning For Offensives

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 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 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, although militarily pointless, circumnavigation of the entire Union Army from June 12 to June 15) and found it vulnerable.

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.

McClellan also planned an offensive. He had received intelligence that Lee was prepared to move and that the arrival of Maj. Gen. Thomas J. "Stonewall" Jackson's force from the 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.) 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.