strong rear guard for the withdrawal, resulting in numerous men from Brig. Gen. George A. McCall's division being captured by the advancing Confederates. Porter selected a new defensive line on a plateau behind Boatswain's Swamp, just to the southeast of a mill owned by Dr. William F. Gaines. It was a strong position, with two divisions laid out in a semicircle—Brig. Gen. George W. Morell on the left and Brig. Gen. George Sykes on the right—and two divisions in reserve—Brig. Gen. George A. McCall and Brig. Gen. Henry W. Slocum, the latter on loan to Porter from Brig. Gen. William B. Franklin's VI Corps. Slocum's division had not crossed the river by the start of the battle, held up by McClellan's concern about an impending attack on Franklin's front. Lee's offensive plan for June 27 was similar to that of the preceding day. He would use A.P. Hill's and Longstreet's divisions to pressure Porter's corps as it withdrew, while Stonewall Jackson, augmented by D.H. Hill (Jackson's brother-in-law), hit Porter's right and rear. The combined effort of all of Lee's force was destined to be the largest Confederate attack of the war, about 57,000 men in six divisions. Lee traveled to Walnut Grove Church to meet with Jackson and describe the plan, which called for Jackson to march toward Old Cold Harbor, and then south beyond Porter's flank. Unfortunately, Lee made incorrect assumptions about Porter's disposition. He assumed that the V Corps would defend the line of Powhite Creek, somewhat to the west of Porter's actual location. Opposing forces Union Confederate Battle The first actions of the battle occurred between noon and 1 p.m. on June 27 after D.H. Hill's division reached Old Cold Harbor, where it was scheduled to link up with Stonewall Jackson's command. Hill pushed through the crossroads with two brigades, which encountered unexpected infantry fire. Seeking to suppress the fire, he brought forward the Jeff Davis Battery from Alabama, but it was soon outgunned by two six-gun batteries manned by U.S. regulars from Brig. Gen. George Sykes's division. Hill was surprised at the level of resistance and also that he seemed to be meeting the front of the Union force, not the expected flank, so he determined to wait for Jackson's arrival before moving further. The noise from this engagement failed to reach General Lee at his headquarters, the house owned by William Hogan, named "Selwyn". A.P.