Gaines' Mill

Fought on June 27, 1862, in Hanover County, Virginia, the clash sometimes called the Battle of Chickahominy River ranked as the third engagement in the Seven Days Battles, a sequence that together determined how the Union's Peninsula Campaign in the Civil War would end. A day earlier, the fighting at Beaver Dam Creek near Mechanicsville had ended without a clear result, and afterward Lee pressed forward again, targeting the exposed right side of the Union army positioned north of the Chickahominy. In that area, Fitz John Porter's V Corps had dug in along a solid line behind Boatswain's Swamp. What Lee was about to unleash would become the war's single largest Confederate assault, roughly 57,000 soldiers organized into six divisions. Through the afternoon Porter's strengthened corps managed to hold its ground even as Confederate forces struck in uncoordinated waves, beginning with A.P. Hill's division and followed by Richard S. Ewell's, both absorbing steep losses in the process. Stonewall Jackson's troops showed up late, which kept Lee from massing his full strength before Porter got some help from the VI Corps.

As evening fell, Confederate forces finally synchronized their assault, shattering Porter's defenses and pushing his troops back toward the river. Under cover of darkness the Federal soldiers crossed the Chickahominy in retreat, and the Confederates, thrown into disarray themselves, could not chase down the bulk of the Union army. This outcome preserved Richmond for the Confederacy that year; despite winning tactically, the defeat pushed McClellan, commanding the Army of the Potomac, to call off his push toward Richmond and pull back instead toward the James River. Nearly two years afterward, the Battle of Cold Harbor would unfold on almost this same ground.

Background

By late May 1862, McClellan's Army of the Potomac had advanced to within a few miles of Richmond, the Confederate capital, but the Battle of

Battle

Fighting began between noon and one o'clock on June 27, once D.H. Hill's division arrived at Old Cold Harbor, where it was meant to join forces with Stonewall Jackson. Two of Hill's brigades pushed through the crossroads and ran into infantry fire nobody had anticipated. To silence it, Hill called up the Jeff Davis Battery from Alabama, only to have it overwhelmed by a pair of six-gun batteries manned by regulars from Brig. Gen. George Sykes's division. Surprised both by the strength of the resistance and by the discovery that he faced the enemy's front rather than its flank, Hill chose to hold his position until Jackson could arrive. The sound of this clash never carried back to Lee's headquarters at Selwyn, the home of William Hogan.

Meanwhile A.P. Hill's division had crossed Beaver Dam Creek that morning and found the old Union line thinly held. As his men pushed east toward Gaines' Mill, roughly when D.H. Hill's troops became engaged, Porter formally requested that McClellan send Slocum's division over the Chickahominy by way of Alexander's B

Aftermath

Few clashes in the Seven Days matched the ferocity of Gaines' Mill, and none produced a battlefield outcome so squarely in the Confederacy's favor; it stands as the campaign's only unambiguous tactical win for Lee's army. Of the 34,214 Union troops committed, 6,837 fell as casualties, a toll broken down into 894 dead, 3,107 wounded, and 2,836 taken prisoner or unaccounted for. The Confederates, having thrown 57,018 men into the fight, suffered even more heavily: 7,993 casualties in all, with 1,483 killed, 6,402 injured, and 108 missing or captured. Their losses included three brigade commanders and a general officer, a stark contrast to the Union side, where no general died or was hurt, and only Col. Warren fell among brigade leaders, and he stayed in the fight despite his wounds. Maj. Henry DeHart, serving as chief of McCall's artillery, also received a fatal wound. Because the Confederate onslaught struck only a fraction of the Union force, namely the reinforced V Corps, roughly a third of McClellan's total strength, the army as a whole came through the engagement in reasonably sound condition.

This marked Lee's first triumph of the conflict, though it might have been decisive rather than partial had Stonewall Jackson's movements gone more smoothly. According to historian Stephen W. Sears, had Jackson's staff work been sharper and his march not gone astray, Lee's massive evening assault, which finally erupted around 7 p.m., might have begun three or four hours sooner. Such timing would have left Porter's men in a far more desperate position, denied both the reinforcements that arrived at the last moment and the shelter of nightfall. Sears cites the postwar assessment of Edward Porter Alexander, a noted Confederate artillerist, who observed that an earlier assault by Jackson, whether at his initial arrival or alongside A.P. Hill's attack, would have yielded an easy victory and likely the capture of most of Porter's command.

McClellan had already been considering a move of his supply base to the James River, but the shock of this defeat rattled him badly, prompting a hasty decision to give up his push toward Richmond and pull his whole army back toward the James instead. Beyond its tactical significance, Gaines' Mill and the subsequent Union withdrawal over the Chickahominy carried heavy symbolic weight, convincing many that Richmond had escaped its gravest danger.