On June 26, 1862, Gen. Robert E. Lee initiated an offensive against Maj. Gen. George B. McClellan’s isolated right flank north of the Chickahominy River. Brig. Gen. A.P. Hill threw his division into a series of futile assaults against Brig. Gen. Fitz John Porter’s V Corps near Mechanicsville along Beaver Dam Creek. Confederate attacks were driven back with heavy casualties. Maj. Gen. Thomas J. “Stonewall” Jackson’s Shenandoah Valley division, just arrived on the battlefield, forced Porter to withdraw that evening to a position just beyond Gaines’ Mill. The action began a week of near-constant combat known as the Seven Days battles that would force McClellan from the gates of Richmond and establish Lee’s offensive dominance.