his division and A.P. Hill's, while Magruder had his division, Jones, and McLaws in the reserve wing. Brig. Gen Richard H. Anderson and Brig. Gen William H.C. Whiting had operational command of Longstreet and Smith's divisions. Johnston's plan Johnston, who had retreated up the Peninsula to the outskirts of Richmond, knew that he could not survive a massive siege and decided to attack McClellan. His original plan was to attack the Union right flank, north of the Chickahominy River, before McDowell's corps, marching south from Fredericksburg, could arrive. However, on May 27, the same day the Battle of Hanover Court House was fought northeast of Richmond, Johnston learned that McDowell's corps had been diverted to the Shenandoah Valley and would not be reinforcing the Army of the Potomac. He decided against attacking across his own natural defense line, the Chickahominy, and planned to capitalize on the Union army's straddle of the river by attacking the two corps south of the river, leaving them isolated from the other three corps north of the river. If executed correctly, Johnston would engage three quarters of his army (22 of its 29 infantry brigades, about 51,000 men) against the 33,000 men in the III and IV Corps. The Confederate attack plan was complex, calling for the divisions of A. P. Hill and Magruder to engage lightly and distract the Union forces north of the river, while Longstreet, commanding the main attack south of the river, was to converge on Keyes from three directions: six brigades under Longstreet's immediate command and four brigades under D. H. Hill were to advance on separate roads at a crossroads known as Seven Pines (because of seven large pine trees clustered at that location); three brigades under Huger were assigned to support Hill's right; Whiting's division was to follow Longstreet's column as a reserve. The plan had an excellent potential for initial success because the division of the IV Corps farthest forward, manning the earthworks a mile west of Seven Pines, was that of Brig. Gen. Silas Casey, 6000 men who were the least experienced and equipped in Keyes's corps. If Keyes could be defeated, the III Corps, to the east, could be pinned against the Chickahominy and overwhelmed. The complex plan was mismanaged from the start. Johnston chose to issue his orders to Longstreet orally in a long and rambling meeting on May 30. The other generals received