The Battle of Gaines' Mill, also known as the Battle of Chickahominy River, took place on June 27, 1862, in Hanover County, Virginia, as the third of the Seven Days Battles which together decided the outcome of the Union's Peninsula campaign of the American Civil War. Following the inconclusive Battle of Beaver Dam Creek (Mechanicsville) the previous day, Confederate General Robert E. Lee renewed his attacks against the right flank of the Union army, relatively isolated on the northern side of the Chickahominy River. There, Brig. Gen. Fitz John Porter's V Corps had established a strong defensive line behind Boatswain's Swamp. Lee's force was destined to launch the largest Confederate attack of the war, about 57,000 men in six divisions. Porter's reinforced V Corps held fast for the afternoon as the Confederates attacked in a disjointed manner, first with the division of Maj. Gen. A.P. Hill, then Maj. Gen. Richard S. Ewell, suffering heavy casualties. The arrival of Maj. Gen. Stonewall Jackson's command was delayed, preventing the full concentration of Confederate force before Porter received some reinforcements from the VI Corps.
At dusk, the Confederates finally mounted a coordinated assault that broke Porter's line and drove his men back toward the Chickahominy River. The Federals retreated across the river during the night. The Confederates were too disorganized to pursue the main Union force. Gaines' Mill saved Richmond for the Confederacy in 1862; the tactical defeat there convinced Army of the Potomac commander Maj. Gen. George B. McClellan to abandon his advance on Richmond and begin a retreat to the James River. The battle occurred in almost the same location as the Battle of Cold Harbor nearly two years later.
Background
Military situation
McClellan's Army of the Potomac had pushed to within a few miles of the Confederate capital of Richmond and had stalled following the Battle of Seven Pines in late May 1862. Lee wanted to take the initiative, believing that remaining on the strategic defensive would play into Union hands and allow the Confederacy to be worn down. He planned to shift his 90,000-man Confederate army to the north of Richmond, and attack McClellan's right flank. The Confederate cavalry under the command of Maj. Gen. J.E.B. Stuart had ridden around McClellan's army, confirming that the flank was open—not anchored on Totopotomoy Creek—and vulnerable. Lee planned to use Maj. Gen. Stonewall Jackson's force, transported by rail from the Shenandoah Valley, to attack on McClellan's right and rear, while the remainder of his army under Maj. Gens. A.P. Hill, James Longstreet, and D.H. Hill attacked from the direction of Mechanicsville.
The Seven Days Battles began with a Union attack in the minor Battle of Oak Grove on June 25, but the first major battle started the next day when Lee launched a large-scale assault against McClellan at the Battle of Beaver Dam Creek (or Mechanicsville). Lee attacked Porter's V Corps north of the Chickahominy, while the bulk of the Union Army was relatively unoccupied south of the river. Although this battle was a tactical victory for the Union, McClellan realized that he could not keep Porter's corps in place with Jackson threatening his flank. He ordered Porter to begin a withdrawal and at the same time decided to change the army's base of supply from White House on the Pamunkey River to Harrison's Landing on the James River. (This decision was fatal to McClellan's campaign because by abandoning the railroad that led from the Pamunkey, he would no longer be able to supply his planned siege of Richmond with the necessary heavy artillery.)
Several of McClellan's subordinates urged him to attack the Confederate division of Maj. Gen. John B. Magruder south of the Chickahominy, but he feared the vast numbers of Confederates he believed to be before him and failed to capitalize on the overwhelming superiority he actually held on that front. Magruder assisted in this misapprehension by ordering frequent, noisy movements of small units back and forth and by using groups of slaves with drums to simulate large marching columns. Furthermore, the Union Army Balloon Corps, which had performed the only aerial observation during the Peninsula Campaign, was now joined by a Confederate competitor. Capt. Langdon Cheves of South Carolina had constructed a multicolored balloon of dress silk obtained from Charleston and Savannah, which sailed aloft tethered to a boxcar on the York River Railroad, manned by Maj. Edward Porter Alexander. The appearance of this balloon reinforced McClellan's fear that the Confederates were planning for an offensive against his left flank. For the second day, the Confederates were able to continue fooling McClellan south of the river by employing minor diversionary attacks to command the attention of 60,000 Federal troops while the heavier action occurred north of the river.
The order to Porter's corps came just before dawn and they did not have adequate time to prepare a 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.
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. Hill's division had moved across Beaver Dam Creek early in the morning, finding the former Union line lightly defended. As they proceeded eastward and approached Gaines' Mill at about the time that D.H. Hill's men were engaged, Porter formally asked McClellan to send Slocum's division across the Chickahominy over Alexander's Bridge to support him. Hill directed the brigades of Maxcy Gregg and Lawrence O'Bryan Branch to spearhead the assault, as they had not been engaged at Beaver Dam Creek and were well-rested. Gregg was held up by skirmishers from Col. Hiram Berdan's 1st U.S. Sharpshooters and the 9th Massachusetts Infantry. By early afternoon, he had run into strong opposition by Porter, deployed along Boatswain's Creek, and the swampy terrain was a major obstacle against the advance. A particularly bloody engagement occurred as the 1st South Carolina Rifles attacked a Massachusetts battery, but were repulsed by Zouaves of the 5th New York, which inflicted 57% casualties (76 killed, 221 wounded, and 58 missing) on the South Carolinians, the greatest Confederate regimental losses of the day. Branch's brigade fared no better, losing 401 men in two hours of fighting. Following behind them, Joseph R. Anderson's brigade launched three assaults on the Union lines without putting a dent in them. Field's brigade became bogged down in the swamp, and some of the men in the rear ended up firing into their comrades. Some of Gregg's men reached the other side of the creek; none of the rest came close.
Instead of pursuing a fleeing enemy, as his orders had directed, A.P. Hill attacked an entrenched Union position, losing about 2,000 of his 13,200 men in the failed attempt. Combined with his attacks at Mechanicsville the previous day, the Light Division had lost over a quarter of its men. General McClellan was encouraged by the telegrams Porter had sent back to his headquarters a few miles to the rear. He replied, "If the enemy are retiring and you are a chasseur, pitch in." He also told Franklin to cross the river over the Duane bridge and attack the enemy's flank if he saw a chance, but he was dismayed to hear that the VI Corps commander had destroyed the bridge for fear of a possible enemy attack. At the same time, Brig. Gen. Edwin V. Sumner of the II Corps reported enemy activity in his front. McClellan's optimism was dashed, and he ordered that his headquarters' equipment be packed up in preparation for the retreat. On the Confederate side, General Lee had been an active participant in the failed assault, rallying his troops too close to the front for their comfort. As Longstreet arrived to the southwest of A.P. Hill, he saw the difficulty of attacking over such terrain and delayed until Stonewall Jackson could attack on Hill's left.
For the second time in the Seven Days, however, Jackson was late. A guide from the 4th Virginia Cavalry, Pvt. John Henry Timberlake, had misunderstood Jackson's intent and led him down the wrong road. After they counter-marched, losing about an hour, Jackson's troops found the road to Old Cold Harbor obstructed by trees felled by the retreating Union army and were harassed by sharpshooters, delaying their arrival. The first of Jackson's command to reach the battlefield was the division of Maj. Gen. Richard S. Ewell, who was met by Lee's aide, Walter Taylor, and instructed to move into action immediately. Lee was concerned that Porter would counterattack the weakened troops of A.P. Hill, so he ordered Longstreet to conduct a diversionary attack to stabilize the lines until Jackson's full command could arrive and attack from the north. In Longstreet's attack, Brig. Gen. George E. Pickett's brigade attempted a frontal assault and was beaten back under severe fire with heavy losses. Pickett himself took a bullet to the shoulder, putting him out of action for the rest of the summer; Col. Eppa Hunton of the 8th Virginia assumed command of the brigade. Confederate President Jefferson Davis was among the party witnessing Pickett's failed attempt.
Ewell began his attack immediately, around 3:30 p.m., without waiting for his entire division to come on line. General Lee's instructions were to advance along the same axis used by the brigades of Gregg and Branch, to maintain the momentum of the attack. He sent in his lead brigade, Louisianans under Col. Isaac Seymour, commanding in Maj. Gen. Richard Taylor's absence for medical reasons. Seymour was relatively inexperienced and his troops became confused in the woods and bogs of Boatswain's Swamp. Their confusion increased when Col. Seymour was killed by a Union rifle volley. Maj. Roberdeau Wheat, the colorful leader of the Louisiana Tigers Battalion, moved to the front to lead the brigade, but he was also killed with a bullet through his head. The Louisiana Brigade withdrew from the battle. Ewell's attack continued with two regiments from the brigade of Brig. Gen. Isaac R. Trimble, but they could not advance beyond the swamp, falling with about 20% casualties. Porter was starting to receive reinforcements from Slocum's division and he brought forward troops to feed into gaps in his line. However, despite telegrams from Porter for more assistance, General McClellan gave no thought to the advantages of a counterattack. He asked his corps commanders south of the river whether they had any troops they could spare. When no one volunteered, he directed Sumner of the II Corps to send two brigades—about one tenth of the army—across the river, but because of the distances involved they would not reach the scene for another three hours.