text: Planning for offensives Lee's initial attack plan, similar to Johnston's plan at Seven Pines, paper 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 but militarily dubious circumnavigation of the entire Union Army from June 12 to 15—and found it vulnerable.