Battle of Mechanicsville

Battle of Mechanicsville (also known as Beaver Dam Creek or Ellerson's Mill)
Campaign	Seven Days' Battles, the Peninsula Campaign
Date	June 26, 1862
Location	Vicinity of Ellerson's Mill, Beaver Dam Creek, and the village of Mechanicsville
Combatants
United States	Confederacy
Commanders
George B. McClellan	Robert E. Lee
Strength Engaged
15,361	16,356
Casualties
361 (49 killed, 207 wounded, and 105 missing or captured)	1,484

The Battle of Mechanicsville on June 26, 1862, marked the beginning of the Seven Days' Campaign during the American Civil War (1861–1865). Union general George B. McClellan had marched his Army of the Potomac up the Peninsula, his campaign against the Confederate capital at Richmond stalling out at the Battle of Seven Pines–Fair Oaks (May 31–June 1, 1862). When Confederate commander Joseph E. Johnston was seriously wounded in the fighting, Robert E. Lee assumed command of the Army of Northern Virginia and went on the offensive, attacking McClellan's forces on June 26 near Mechanicsville, along a creek known as Beaver Dam Run. Lee created a complicated battle plan that depended upon Thomas J. "Stonewall" Jackson's men meeting up with Confederate forces and signaling A. P. Hill to begin his attack. Unfortunately, Jackson was running late, and when Hill attacked anyway, Confederate forces were repulsed by Union troops who were well protected by the creek and artillery on the high ground. Despite his victory, however, McClellan decided to pull his troops back to Gaines's Mill. Lee attacked and defeated him there the next day.

Background

In May 1862, McClellan had cautiously maneuvered the Army of the Potomac up the Peninsula—his critics suggested his pace was glacial—taking a month to overcome Confederates at Yorktown (April 5–May 4) and winning another victory at Williamsburg on May 5. Soon he was on the outskirts of Richmond, his forces outnumbering the capital's beleaguered defenders; victory seemed imminent. While a Confederate attack at Seven Pines failed to secure any tactical gains, it wounded Joseph Johnston sufficiently that he was forced to hand his command over to Robert E. Lee, who before then was known largely for having lost western Virginia to McClellan. While the Union general continued to plod along, Lee sought to seize the initiative.

Lee decided to advance on McClellan's right wing, which lay north of the Chickahominy River. By launching an attack there, he could push east and attempt to cut Union troops off from their supply depot at White House Landing on the Pamunkey River. A reconnaissance by the flamboyant Confederate cavalryman J. E. B. Stuart had revealed that McClellan's flank was "in the air," meaning that it was not anchored on some natural obstacle it could use for defense. Troops under Jackson were to link up with Confederate forces on the Chickahominy River, and then relay word to Confederate general A. P. Hill, who would cross the river, march through Mechanicsville, and attack Union general Fitz-John Porter's Fifth Corps, positioned behind the waist-deep Beaver Dam Run. Confederate forces under D. H. Hill and James Longstreet would follow him.

The Battle

Lee's intricate plan was immediately thwarted when Jackson's men, fatigued from the Shenandoah Valley Campaign and their recent march to Richmond, failed to arrive on time. At three o'clock in the afternoon, an impatient and impetuous A. P. Hill attacked anyway, but his men were forced to march across an open field and then wade across the creek before attempting to overcome Union infantry supported by artillery on the high ground. Pennsylvanians under Union general John F. Reynolds pushed Hill's troops back.

Jackson's men began to arrive at their designated meeting place, three to four miles from the battlefield, around five o'clock, but instead of joining the fight, Jackson ordered his men to make camp. That left A. P. Hill to attempt another attack at dusk, this time on Porter's left flank, defended by Union general Truman Seymour. Lieutenant John Hinsdale, an aide to Confederate general Dorsey Pender, described the battle: "I never saw such a storm of shot and shells before. Fragments of shells literally hailed around me. I thought my life was worth very little … The noise was deafening." By nine o'clock, fighting had tapered off.

Aftermath

The battle was a defeat for the Confederates, who suffered about 1,400 casualties compared to Union losses that numbered less than half that figure. Still, Lee's aggression—so different from how Joseph Johnston had fought—prompted McClellan to withdraw his army rather than pursue Lee's. Fitz-John Porter's Fifth Corps was ordered to retreat to Gaines's Mill, where Lee attacked it the next day. Jackson's troops were slow to arrive then, too, but the battle was a Confederate victory. Although the Seven Days' Battles had just begun, McClellan's ambitious campaign against Richmond had already failed.

Time Line

June 18, 1862 - Having cleaned the Shenandoah Valley of Union troops, Confederate general Thomas J. "Stonewall" Jackson begins the march to Richmond, where his men will reinforce Robert E. Lee outside the city.
June 26, 1862, 2:00–3:00 a.m. - At the Battle of Mechanicsville, Confederate generals D. H. Hill and James Longstreet fall into position behind A. P. Hill's men on the Chickahominy River. They are to await the arrival of Thomas J. "Stonewall" Jackson before attacking Union forces.
June 26, 1862, 3:00 p.m. - At the Battle of Mechanicsville, Confederate general A. P. Hill is ordered to await the arrival of Thomas J. "Stonewall" Jackson before crossing the Chickahominy River and attacking Union forces. When Jackson doesn't show, Hill attacks anyway and is repulsed.
June 26, 1862, 5:00 p.m. - During the Battle of Mechanicsville, Confederate general Thomas J. "Stonewall" Jackson reaches his designated meeting place but finds no other troops there. Rather than march to the sound of fighting, he orders his men to make camp. A. P. Hill, meanwhile, orders an assault on the Union left.
June 26, 1862, 9:00–10:00 p.m. - Fighting tapers off at the Battle of Mechanicsville. Confederate troops are forced to attack across an open field and then a waist-deep creek, and are pushed back by the Union Fifth Corps under Fitz-John Porter.
June 27, 1862, 1:00 a.m. - Despite his victory at the Battle of Mechanicsville, Union general George B. McClellan decides to withdraw from his strong position along the banks of Beaver Dam Run and fall back toward Gaines's Mill. Robert E. Lee will attack him there later in the day.