Battle of Gaines’s Mill (also known as the First Battle of Cold Harbor and the Battle of Chickahominy River)
CampaignSeven Days’ Battles, the Peninsula Campaign
DateJune 27, 1862
LocationHanover County, Virginia
United StatesConfederacy
Fitz-John PorterRobert E. Lee
6,837 (894 killed, 3,114 wounded, 2,829 captured)7,993 (1,483 killed, 6,402 wounded, 108 missing)

Gaines’s Mill, Battle of


The Battle of Gaines’s Mill, fought on June 27, 1862, and one of the Seven Days’ Battles, was a Confederate victory and remembered by many of its participants as the most intense fight of the American Civil War (1861–1865). As Confederate general Thomas J. “Stonewall” Jackson arrived with his troops from the Shenandoah Valley, Robert E. Lee determined to take the offensive against Union general George B. McClellan and his Army of the Potomac, which threatened the Confederate capital at Richmond. On June 26, Lee was turned back at Mechanicsville, but McClellan retreated anyway. The following day at Gaines’s Mill—named for the nearby grist mill of Dr. William Gaines—Lee attacked again, finding Union troops positioned behind a stream that was entirely absent from Confederate maps. While Richmond’s elite looked on, Confederate generals A. P. Hill and Richard S. Ewell charged up a steep hill, suffering horrific casualties, before Jackson’s men—late-arriving and slow to engage—finally joined the fight. At dusk, the battle turned in the Confederates’ favor, and an evening cavalry charge led by Union general Philip St. George Cooke was a costly failure. In nine ghastly hours of fighting, Union and Confederate casualties totaled about 15,000 men.


In May and June of 1862, Union general George B. McClellan had sailed his Army of the Potomac down the Chesapeake Bay and then slowly and deliberately marched it up the Peninsula in an attempt at taking the Confederate capital at Richmond from the southeast. The campaign culminated in stalemate at the Battle of Seven Pines–Fair Oaks on May 31–June 1, 1862. When the Confederate commander, Joseph E. Johnston, was severely wounded, Robert E. Lee assumed command of the Army of Northern Virginia and immediately went on the offensive.

The Battle of Mechanicsville (Beaver Dam Run) on June 26 was a Union victory, but McClellan nevertheless retreated from his position on the outskirts of Richmond. In part, he was wary of Jackson’s troops, who had just arrived from the Shenandoah Valley after winning the battles of Cross Keys and Port Republic. His fears were also fueled by a great deal of noise and movement coming from the Confederate lines—an elaborate deception orchestrated by Confederate general and theater enthusiast John B. Magruder—and the appearance of a silk hot air balloon reconnoitering from high above the area. McClellan ordered the Fifth Corps under Union general Fitz-John Porter to protect his retreat route while the rest of the army withdrew to the safety of the James River.

It never occurred to Lee that McClellan would retreat after just one battle—and a Union victory at that. He met with Jackson and A. P. Hill at Walnut Grove Church and formulated a plan that would either cut Union supply lines or force a battle. Jackson and Daniel Harvey Hill were to attack McClellan’s supply line to the northeast, while A. P. Hill and James Longstreet pressured Porter’s Fifth Corps from the west, driving it into a trap. The Confederates army’s inexcusably poor knowledge of the local geography, however, would interfere with the execution of Lee’s plan.

The Battle

To make his stand, Porter selected a plateau encircled at its base by the marshy stream known as Boatswain Swamp. The attacking Confederates would have to make their way across a long, sloping field, through a boggy creek, and up a steep hillside protected by thick underbrush and rows of Union infantrymen, all the while enduring the punishing fire of artillery arrayed across the hilltop. Lee was surprised to learn that the enemy had withdrawn behind Boatswain Swamp, which appeared on none of his maps. Believing McClellan was massing his entire army against him, Lee accepted the challenge.

Confederates Advancing to the capture of disabled guns

Porter observed the gathering Confederate lines and, suspecting his enemy’s intention to “overwhelm and crush” him, finally requested reinforcements. They had not yet arrived when the Confederates, under A. P. Hill, launched their initial assault that afternoon. The fighting was so intense that one Union soldier remarked, “Hell itself seemed to break loose.” With cannon blasting down from the hilltop, the two-hour charge resulted in more than 2,000 casualties. Eager to maintain momentum, Lee urged three brigades under Richard S. Ewell to continue the attack on the Union center. The Confederates suffered high casualties in several ferocious charges, which Ewell boldly commanded on foot after his horse was killed beneath him. The Union troops managed to hold their line through Boatswain Swamp, although the fighting entirely depleted their ammunition.

Confederate president Jefferson Davis and other prominent Richmonders had gathered to watch the battle from safely behind Confederate lines. An unusual occurrence known as an “acoustic shadow,” created by pockets of dense moist air, prevented the onlookers from hearing the sounds of battle, although the fighting was only a few miles distant. The only action they could readily observe was Longstreet’s force on the far right of the Confederate line. Lee had ordered him to create a diversion, the failure of which was apparent to everyone as lines of men streamed to the rear. Unaware that this was merely a distraction, Porter wired McClellan that he was “pressed hard, very hard” and feared being driven from his position.

By late afternoon, Jackson had finally arrived, but further miscommunication resulted in his awaiting further orders rather than advancing onto the field. The error was eventually discovered, and the Stonewall Brigade moved forward in the fading sunlight with a sense of urgency. The Virginia soldiers joined the final charge, which progressed unevenly across the field, through the swamp, and up the steep hill. The narrow hilltop allowed little room for maneuvering, so the ensuing battle was a heated contest of brute force. Eventually, the Union line broke in several places almost simultaneously, although the 4th Texas and 18th Georgia infantry regiments are generally credited with initiating the breakthrough. The fighting was brutal; in the words of one Texas soldier, “One volley was poured into their backs, and it seemed as if every ball found a victim, so great was the slaughter.” The Confederates pursued the fleeing Union troops across an open field, through tangled swampland, and across the Chickahominy River.

As the Confederates advanced on a second line of Union artillery, they were amazed to find themselves suddenly under attack by Union cavalry led by Philip St. George Cooke, the father-in-law of Confederate general J. E. B. Stuart. The Confederates unleashed a withering fire that immediately dropped one-fourth of the oncoming cavalrymen. Most of the remaining troopers veered away from the Confederates, although a few charged directly into enemy lines and were promptly bayoneted. Porter would later blame Cooke’s charge for that day’s defeat, although in reality the Confederates had all but cinched their victory.

The Aftermath

The splintering Union line and deepening darkness gradually brought the battle to a close. Reinforcements arrived as the bulk of the army was retreating, but had little hope of reversing fortunes. Two entire Union regiments—nearly a thousand men—surrendered to Confederates after finding themselves surrounded by the enemy. Union forces also had twenty-two pieces of artillery captured, although the number of their killed and wounded—about 4,000 men—was significantly smaller than that of the attacking Confederates, who suffered almost 8,000 casualties.

Many veterans would remember the nine hours at Gaines’s Mill as the most vicious fighting of the entire war. McClellan soon declared publicly what he had already decided privately: that he would abandon his campaign against the Confederate capital. Lee, meanwhile, earned the confidence of the Army of Northern Virginia and President Davis, although the rest of the Seven Days’ Campaign would fail to destroy the Union army.

June 27, 1862, 1:00 a.m.
As the Army of the Potomac retreats from the outskirts of Richmond, Union general George B. McClellan leaves Fitz-John Porter and his Fifth Corps to protect his withdrawal against Confederate attack.
June 27, 1862, 7:00 a.m.
Confederate general Robert E. Lee arrives in Mechanicsville with the intention of cutting Union general George B. McClellan's supply line or forcing a fight, not realizing that the majority of McClellan's Army of the Potomac is now retreating.
June 27, 1862, 9:30 a.m.
Union balloonist Thaddeus Lowe observes intense movement along the Confederate lines and reports that an attack is coming "at any moment." To his surprise, he also sees a Confederate balloon floating near Richmond, engineered by Captain Langdon Cheves and piloted by Porter Alexander.
June 27, 1862, 12:00 p.m.
Heading toward the Chickahominy River, Confederate general D. H. Hill's two brigades unexpectedly encounter a substantial force of Union troops. Suffering artillery fire, Hill determines to wait for Thomas J. "Stonewall" Jackson before advancing, but has no way of notifying Robert E. Lee of the enemy's new position.
June 27, 1862, 1:00 p.m.
During the Battle of Gaines's Mill, Confederate general A. P. Hill sends reinforcements to Maxcy Gregg's South Carolinian brigade at the center of the Confederate line.
June 27, 1862, 2:30 p.m.
During the Battle of Gaines's Mill, infantry under Confederate general A. P. Hill advances in a bloody and futile charge that lasts two hours.
June 27, 1862, 3:30 p.m.
Meeting up with Confederate general Richard S. Ewell on Telegraph Road, Robert E. Lee instructs him to lead his three brigades into battle. He also has instructed James Longstreet to create a diversion on the Confederate right, so as to divide Union attention and forces.
June 27, 1862, 4:00 p.m.
During the Battle of Gaines's Mill, Union general Henry Slocum arrives with the Sixth Corps to reinforce Fitz-John Porter's Fifth Corps.
June 27, 1862, 4:30 p.m.
During the Battle of Gaines's Mill, Confederate general Thomas J. "Stonewall" Jackson meets Robert E. Lee on Telegraph Road, having been delayed by inaccurate maps and miscommunication. After a brief discussion, Jackson returns to deploy his troops onto the field.
June 27, 1862, 7:30 p.m.
At the Battle of Gaines's Mill, Confederates initiate their final attack of the day against Union troops.
June 27, 1862, 8:00 p.m.
As the sun sets at the Battle of Gaines's Mill, the Union 5th Cavalry under Philip St. George Cooke sweeps onto the field to enable the safe removal of the artillery, but is promptly decimated. Triumphant Confederates climb atop captured cannon and wave their flags to signal victory.
  • Krick, Robert E. L. “The Men Who Carried This Position Were Soldiers Indeed: The Decisive Charge of Whiting’s Division at Gaines’s Mill.” In The Richmond Campaign of 1862: The Peninsula and the Seven Days, ed. Gary W. Gallagher. Chapel Hill: University of North Carolina Press, 2000.
  • Sears, Stephen W. To the Gates of Richmond: The Peninsula Campaign. New York: Ticknor and Fields, 1992.
APA Citation:
Wright, Aerika. Gaines’s Mill, Battle of. (2020, December 07). In Encyclopedia Virginia.
MLA Citation:
Wright, Aerika. "Gaines’s Mill, Battle of" Encyclopedia Virginia. Virginia Humanities, (07 Dec. 2020). Web. 23 Jun. 2024
Last updated: 2021, February 12
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