American Civil War: Battle of Seven Pines (Fair Oaks)

Seven Pines
Battle of Seven Pines. Photograph Courtesy of the Library of Congress

The Battle of Seven Pines took place May 31, 1862, during the American Civil War (1861-1865) and represented the farthest advance of Major General George B. McClellan's 1862 Peninsula Campaign. In the wake of the Confederate victory at the First Battle of Bull Run on July 21, 1861, a series of changes commenced in the Union high command. The following month, McClellan, who had won a series of minor victories in western Virginia was summoned to Washington, DC and tasked with building an army and capturing the Confederate capital at Richmond. Constructing the Army of the Potomac that the summer and fall, he commenced planning his offensive against Richmond for the spring of 1862.

To the Peninsula

To reach Richmond, McClellan sought to transport his army down the Chesapeake Bay to Union-held Fortress Monroe. From there, it would push up the Peninsula between the James and York Rivers to Richmond. This approach would permit him to flank and avoid General Joseph E. Johnston's forces in northern Virginia. Moving forward in mid-March, McClellan began shifting around 120,000 men to the Peninsula. To oppose the Union advance, Major General John B. Magruder possessed approximately 11,000-13,000 men. 

Establishing himself near the old American Revolution battlefield at Yorktown, Magruder built a defensive line running south along the Warwick River and ending at Mulberry Point. This was supported by a second line to the west that passed in front of Williamsburg. Lacking sufficient numbers to fully man the Warwick Line, Magruder used a variety of theatrics to delay McClellan during the Siege of Yorktown.  This allowed Johnston time to move south with the bulk of his army. Reaching the area, Confederate forces swelled to around 57,000.

The Union Advance

Realizing this amounted to less than half of McClellan's command and that the Union commander was planning a large-scale bombardment, Johnston ordered Confederate forces to retreat from the Warwick Line on the night of May 3. Covering his withdrawal with an artillery bombardment, his men slipped away unnoticed. The Confederate departure was discovered the following morning and an unprepared McClellan directed Brigadier General George Stoneman's cavalry and infantry under Brigadier General Edwin V. Sumner to mount a pursuit. 

Slowed due to muddy roads, Johnston ordered Major General James Longstreet, whose division was serving as the army's rearguard, to man a section of the Williamsburg defensive line to buy the retreating Confederates time (Map). In the resulting Battle of Williamsburg on May 5, Confederate troops succeeded in delaying the Union pursuit. Moving west, McClellan sent several divisions up the York River by water to Eltham's Landing. As Johnston withdrew into the Richmond defenses, Union troops moved up the Pamunkey River and established as series of supply bases.

Plans

Concentrating his army, McClellan routinely reacted to inaccurate intelligence that led him to believe that he was significantly outnumbered and displayed the cautiousness that would become a hallmark of his career. Bridging the Chickahominy River, his army faced Richmond with about two-thirds of its strength north of the river and one-third to the south. On May 27, Brigadier General Fitz John Porter's V Corps engaged the enemy at Hanover Court House. Though a Union victory, the fighting led McClellan to worry about the safety of his right flank and made him hesitant to transfer more troops south of the Chickahominy. 

Across the lines, Johnston, who recognized that his army could not withstand a siege, made plans to attack McClellan's forces. Seeing that Brigadier General Samuel P. Heintzelman's III Corps and Brigadier General Erasmus D. Keyes' IV Corps were isolated south of the Chickahominy, he intended to throw two-thirds of his army against them. The remaining third would be used to hold McClellan's other corps in place north of the river. Tactical control of the attack was delegated to Major General James Longstreet. Johnston's plan called for Longstreet's men to fall upon IV Corps from three directions, destroy it, then move north to crush III Corps against the river.   

Armies & Commanders:

Union

  • Major General George B. McClellan
  • around 40,000 engaged

Confederate

  • General Joseph E. Johnston
  • General Gustavus W. Smith
  • around 40,000 engaged

A Bad Start

Moving forward on May 31, the execution of Johnston's plan went badly from the start, with the assault beginning five hours late and with only a fraction of the intended troops participating. This was due to Longstreet using the wrong road and Major General Benjamin Huger receiving orders that did not give a start time for the attack. In position on time as ordered, Major General D.H. Hill's division waited for their comrades to arrive. A 1:00 PM, Hill took matters in his own hands and advanced his men against Brigadier General Silas Casey's IV Corps division.

Hill Attacks

Pushing back the Union skirmish lines, Hill's men launched assaults against Casey's earthworks to the west of Seven Pines. As Casey called for reinforcements, his inexperienced men fought hard to maintain their position. Ultimately overwhelmed, they fell back to a second line of earthworks at Seven Pines. Requesting aid from Longstreet, Hill received one brigade to support his efforts. With the arrival of these men around 4:40 PM, Hill moved against the second Union line (Map).

Attacking, his men encountered the remnants of Casey's division as well as those of Brigadier Generals Darius N. Couch and Philip Kearny (III Corps). In an effort to dislodge the defenders, Hill directed four regiments to attempt to turn IV Corps' right flank.  This attack had some success and forced Union troops back to the Williamsburg Road. Union resolve soon stiffened and subsequent assaults were defeated.

Johnston Arrives

Learning of the fighting, Johnston advanced with four brigades from Brigadier General William H.C. Whiting's division. These soon encountered Brigadier General William W. Burns' brigade from Brigadier General John Sedgwick's II Corps division and began pushing it back. Learning of the fighting to the south of the Chickahominy, Sumner, commanding II Corps, had commenced moving his men over the rain-swollen river. Engaging the enemy to the north of Fair Oaks Station and Seven Pines, the remainder of Sedgwick's men were able to halt Whiting and inflict heavy losses.    

As darkness approached fighting died out along the lines. During this time, Johnston was struck in the right shoulder by a bullet and in the chest by shrapnel. Falling from his horse, he broke two ribs and his right shoulder blade. He was replaced by Major General Gustavus W. Smith as army commander. During the night, Brigadier General Israel B. Richardson's II Corps division arrived and took a place in the center of the Union lines.

June 1

The next morning, Smith resumed attacks on the Union line. Beginning around 6:30 AM, two of Huger's brigades, led by Brigadier Generals William Mahone and Lewis Armistead, hit Richardson's lines. Though they had some initial success, the arrival of Brigadier General David B. Birney's brigade ended the threat after fierce fighting. The Confederates fell back and fighting ended around 11:30 AM. Later that day, Confederate President Jefferson Davis arrived at Smith's headquarters. As Smith had been indecisive, bordering on a nervous breakdown, since Johnston's wounding, Davis elected to replace him with his military advisor, General Robert E. Lee (Map).

Aftermath

The Battle of Seven Pines cost McClellan 790 killed, 3,594 wounded, and 647 captured/missing. Confederate losses numbered 980 killed, 4,749 wounded, and 405 captured/missing. The battle marked the high point of McClellan's Peninsula Campaign and the high casualties shook the Union commander's confidence. In the long term, it had a profound influence upon the war as Johnston's wounding led to the elevation of Lee. An aggressive commander, Lee would lead the Army of Northern Virginia for the remainder of the war and won several key victories over Union forces.

For over three weeks after Seven Pines, the Union army sat idle until the fighting was renewed at the Battle of Oak Grove on June 25. The battle marked the beginning of the Seven Days Battles which saw Lee force McClellan away from Richmond and back down the Peninsula.