text: 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.
  Opposing forces
  The armies that fought in the Seven Days Battles comprised almost 200,000 men, which offered the potential for the largest battles of the war. However, the inexperience or caution of the generals involved usually prevented the appropriate concentration of forces and mass necessary for decisive tactical victories.