The Battle of Cold Harbor (31 May to 12 June 1864) was the final major engagement of the Overland Campaign, the large-scale Union offensive into Virginia in the final year of the American Civil War (1861 to 1865). It marked a devastating defeat for the Union Army of the Potomac, which lost around 7,000 men in just 20 minutes during an assault on 3 June. The battle also saw the transition from the swift maneuverings and bloody battles of the Overland Campaign to the static trench warfare that would characterize the final phase of the war, at the Siege of Petersburg (June 1864 to April 1865).

At the end of May 1864, as the white flowers blossomed on the dogwood trees, two rival armies were beating one another to death in Central Virginia. These two old foes – the dogged Army of the Potomac and the scrappy Army of Northern Virginia – had been locked in a continuous struggle for the last three weeks, ever since the Union troops had first splashed their way across the Rapidan River on 4 May, beginning the Overland Campaign. Since then, two general engagements had been fought, each more hellish than the last. First, the two armies clashed at the Battle of the Wilderness (5 to 6 May), where men fired blindly into the dark trees ahead and forest fires devoured the wounded alive.

Next came the Battle of Spotsylvania Court House (8 to 21 May), where thousands of hapless soldiers fought over a patch of ground later known as the Bloody Angle. For 20 hours straight, men engaged in a desperate hand-to-hand struggle at this point – men were skewered with bayonets, bodies were shot so many times that they became formless lumps of flesh, wounded men were trampled into the mud to drown. By the time the fighting at Spotsylvania finally fizzled out, the campaign had already cost some 50,000 men, killed, wounded, and missing. Over 30,000 of these casualties had been from the Union Army of the Potomac, which had thus far lost an average of 2,000 men a day, a rate of 2 casualties for every 1 suffered by the Confederates. At any previous moment in the war, a Union army that had suffered so grievously would have retreated across the nearest river to lick its wounds.

But the war had changed, and Lieutenant General Ulysses S. Grant, who was conducting the campaign in his capacity as general-in-chief, was no ordinary Union commander. He meant to keep on driving south, whatever the cost, taking advantage of his numerical superiority to continuously hammer the rebel army and bleed it white. By the end of May, he had 109,000 men against 59,000 Confederates – even if he continued to lose more men, he could afford to replace them more easily than the enemy could. All he had to do was keep the pressure on, and eventually, something would break. "I mean to fight it out on this line, if it takes all summer," Grant had written to his superiors in Washington, and, as the army continued south and the death toll climbed, it must have seemed to his soldiers that it was shaping up to be a very long summer indeed (McPherson, 731).

Grant's opponent, General Robert E. Lee, knew that he was at a disadvantage. Not only was he scraping the bottom of the barrel for reinforcements, but his best officers had been knocked out of action during the past few weeks – his dashing cavalry commander J. E. B. Stuart had been killed, his trusty lieutenant James Longstreet seriously wounded, the aggressive Third Corps commander A. P. Hill dangerously sick. Lee himself had come down with a bad case of diarrhea and was forced to plan his next moves from the back of an ambulance. Yet despite these drawbacks, the gray-bearded commander knew that he had to keep moving, lest the Yankee horde slip around him and get between his army and Richmond.

In the week that followed Spotsylvania, the two armies marched south on parallel lines, fighting a series of skirmishes collectively known as the Battle of North Anna (23 to 26 May). But these battles were indecisive, little more than maneuvers as each side looked to gain the upper hand. As the bloodiest month of the Civil War drew to a close, both armies seemed to be heading for the same point – Cold Harbor, a vital crossroads that controlled the path to Richmond. Lee knew that he had to get there before Grant, as he was not sure he could dislodge the larger Union army from that position should he lose the race.

As they had done at Spotsylvania, the Union and Confederate cavalry raced to take control of the crossroads at Cold Harbor, cognizant that whichever side got there last would have to make a costly assault against the other. This time, it was the Yankees who got there first – blue cavalry under Major General Philip H. Sheridan seized control of the crossroads before exchanging fire with an oncoming division of gray horsemen under Fitzhugh Lee, nephew of the Southern general. Throughout the day, the dismounted cavalry troopers fired at one another, with Fitz Lee's men gradually forced to give ground.

General Lee, hoping to aid his young nephew's bid to hold onto the crossroads, rushed in a North Carolina division under Major General Robert Hoke. No sooner had Hoke's men arrived, however, than Fitz Lee's tired cavalrymen began to break, beating a hurried retreat down the road. Hoke's men, tired from their march and unwilling to be left to fight on their own, retreated with them and, by dusk, the Cold Harbor crossroads remained in Union possession.

Despite his small victory, Sheridan was not confident in his ability to hold the crossroads, having learned from rebel prisoners that three more Confederate brigades were on their way. But, under orders from Grant to hold Cold Harbor "at all hazards", Sheridan had no choice but to spend the night throwing up temporary breastworks as he waited for the bulk of the Army of the Potomac to join him (quoted in Foote, 281).

When the sun rose on the stifling hot morning of 1 June, Sheridan found that his worst fears had been realized – elements of the rebel First Corps, under Major General Richard Anderson, were starting to arrive. Hoping to dislodge Sheridan's token force of cavalrymen, Anderson attacked at 8 a.m., sending in a brigade led by Colonel Lawrence Keitt, a former congressman with little military experience.

As Keitt led his men toward the Yankee breastworks, he was shot and killed; watching their colonel pitch forward and tumble from his saddle, his men lost their nerve and ran away. One rebel artillerist watched the shameful display, recalling that "some men were so scared they could not run, but groveled on the ground trying to burrow into the earth" (quoted in Foote, 285). Hoke, whose division had been supposed to come up in support of Keitt's assault, had seen the writing on the wall and never moved at all.

Around midday, Sheridan finally got the reinforcements he had been desperately waiting for. The Union VI Corps under Major General Horatio Wright arrived and began deepening and extending the line of entrenchments begun by the cavalrymen. Grant wanted the VI Corps to attack the rebel positions immediately, but Wright, aware that his men were exhausted from their long march, preferred to wait for the rest of the Union army to come up. The rest of the sweltering afternoon was spent digging, as both armies rushed in reinforcements.

Finally, at 5 p.m., the attack that Grant wanted finally got underway – Wright's corps pushed forward, and the sleepy summer evening came alive with the clatter of rifle fire. One of Wright's brigades managed to penetrate the rebel line but was ultimately pushed back in a swift counterattack. By sunset, the fighting petered out, leaving 2,200 Union and 1,800 Confederate soldiers dead, wounded, or missing. Yet the Union assault had not been for naught, as Wright's corps was now positioned closer to the rebel lines, ready to launch a fresh attack come morning.

On the morning of 2 June, Major General George Gordon Meade stepped outside his headquarters. Despite Grant's supreme authority as general-in-chief, Meade was formally in command of the Army of the Potomac and was determined that said army should continue its bloody work this morning. But Meade's subsequent orders of attack – hasty and vague as they were – met with contention from his corps and division officers, who were not so eager to throw their men into a meatgrinder without a better semblance of a plan.

Indeed, Major General William 'Baldy' Smith, commander of the Union XVIII Corps, argued that Meade's order hardly contained any plan at all, and was "simply an order to slaughter my best troops" (quoted in battlefield.org). Grant, noting both the weariness of the soldiers and the fact that the II Corps was not yet in position, agreed with Smith and instructed Meade to postpone the attack for the next day. Meade unhappily complied.

Once Lee realized that no attack was forthcoming, he ordered his men to make use of this day of rest and start digging. As they had done at Spotsylvania, the rebels dug an impressive network of trenches described by a newspaper reporter as "intricate, zig-zagged lines within lines, lines protecting flanks of lines, lines built to enfilade opposing lines…works within works and works without works" (quoted in McPherson, 735). In other words, the rebels had built a strong series of entrenchments that would be near suicidal to assault outright.

The Union soldiers realized this and despaired, knowing they would be the ones assaulting those trenches the next day. That evening, doomed Yankee soldiers wrote their names and addresses on slips of paper that they pinned to the backs of their coats, so that their bodies could be identified. One soldier took it a step further, writing in his diary, "June 3. Cold Harbor. I was killed" (quoted in Foote, 290). True to his prediction, that soldier was killed the next day, and the blood-stained diary was found in his pockets.

What the Union soldiers could plainly see was not so clear to their generals, who massed their units for a mighty, concentrated attack on the Confederate works on the morning of 3 June. It was a little after 4:30 a.m. when the II, VI, and XVIII Corps – 60,000 men in all – trudged forward through the swirling mists and predawn gloom. As the sun began to rise, the Union soldiers approached the Confederate lines, and the earth shook with the thunderous roar of rebel artillery.

Closer and closer the bluecoats came, a low-pitched cry emanating from their throats as the enemy cannons blew holes in their lines, leaving maimed and dying men to writhe in their wake. Presently, as the Union troops came within rifle range, the trenches came alive with fire and smoke, the terrific crackle of rifle volleys sounding like the tearing of some great sheet of canvas. Men fell, their dying screams caught in their throats, their glazed-over eyes staring out at the brilliant sunrise harkening the breaking of a day they would never see.

On the left flank, Major General Winfield Scott Hancock's II Corps pierced a section of the rebel lines, driving the defenders from their trenches after some brief but bloody hand-to-hand combat. The Confederates, however, wasted no time training their cannons on these captured trenches – now trapped within the entrenchments, the Union soldiers were blasted like fish in a barrel, and were quickly beaten back in a panicked retreat.

Elsewhere, the Union attack did not even make it that far. In the center, Wright's VI Corps became helplessly bogged down by a maelstrom of shot, shell, and bullet, forcing it to withdraw before ever reaching the Confederate position. On the right, the men of Smith's XVIII Corps funneled into two ravines where they became pinned down by horrific rebel fire. The Confederates fired double canister shot into this mass of men, obliterating soldiers into red mist and piles of mangled flesh; it was, as one onlooker described, "deadly, bloody work" (quoted in Trudeau, 286). Before long, Smith, too, was forced to retreat, his men tripping over the remains of their fallen comrades.

The attack was over in only 20 minutes, with over 7,000 Union soldiers killed or wounded in that short time. The rebels had lost less than 1,500. Sharpshooters continued to trade shots throughout the day, and minor skirmishes broke out up and down the line. But by and large, the Union army had made its main effort and had failed spectacularly.

It was over so quickly that many Confederate soldiers had not even realized a major enemy assault had been made, much less repulsed. Yet all they had to do was peek above their trenches to see the carnage that they had inflicted. "The dead covered more than five acres of ground about as thickly as they could be laid," Smith would later lament (quoted in McPherson, 735). Even Grant, who had by now gained a reputation for not caring about casualties, was horrified by the slaughter, later writing, "I regret this assault more than any one I have ever ordered" (ibid). At 1:30 p.m., Grant called off any further operations, and the field once again fell silent, other than the chirping of birds, the occasional burst of rifle fire, and the constant groans of the wounded.

For the next nine days, neither side launched a major assault against the other. Instead, the two armies sat in their respective trenches, in some places only a few yards apart. Patrols skirmished with one another on the fringes of no-man's land, while sharpshooters continued taking shots at men who happened to raise their heads out of the trenches a little too high.

Before long, sharpshooters had become the bane of the regular soldiers. "I hated sharpshooters, both Confederate and Union," a Northern artillerist would recall, "and I was always glad to see them killed" (quoted in Foote, 297). As the men crouched in their trenches, they became infected by lice and redbugs, which burrowed into their flesh that had not seen a bath since the campaign began more than a month ago. In many ways, this scene resembled the static trench warfare of the First World War, still half a century in the future.

Grant spent 4 June tightening his lines. When this was done, he turned his attention to the thousands of wounded Union soldiers who still lay alive but wounded in no-man's land. He wanted to retrieve them, but his pride would not allow him to ask Lee for a truce, since doing so would be tantamount to admitting defeat. Instead, he sent a messenger to Lee, asking that each army be allowed to send unarmed litter bearers into no-man's land to pick up their wounded. But Lee, who had no wounded in that field, refused, insisting instead that Grant could only pick up his wounded under a flag of truce, as was customary.

Thus began a standoff between the two rival commanders that wore on for days, as the wounded men slowly began to expire from their injuries, from thirst, from the heat. It was not until 7 June, four days after the initial assault, that Grant swallowed his pride and agreed to a two-hour truce to collect his wounded. But by then, it was much too late. Of the thousands of Yankees who had fallen wounded on 3 June, only two were found still alive.

As the week continued, Grant looked for ways to extricate his army from its immobile position. Hoping to draw Lee out of his fortifications, he sent a flurry of orders to subordinates throughout Virginia and planned three separate maneuvers. First, Major General David Hunter's army would threaten Confederate supplies in the Shenandoah Valley. Then, Sheridan would lead his cavalry to destroy the Virginia Central Railroad. Grant's third move was to quietly pack up his own army and move across the James River, intending to once again slip around Lee.

The plan worked. On 12 June, the Army of the Potomac slipped across the James, and Lee was forced to act accordingly. He had no choice but to divide his army to meet these threats. The Confederate Second Corps, under Lieutenant General Jubal Early, was dispatched to the Shenandoah to meet Hunter's invasion, while two cavalry divisions were sent in pursuit of Sheridan. The rest of Lee's army disengaged from Cold Harbor and moved to protect Petersburg, a critical railroad junction south of Richmond, and Grant's most likely destination.

And so, the Battle of Cold Harbor was over. 12,737 Union soldiers had been listed killed, wounded, captured, or missing – over half of these casualties occurring during the 20-minute attack of 3 June – compared to only 4,595 Confederate losses. It was one of the most lopsided major battles of the entire war. It was also, as it would turn out, the last major battle won by General Lee and his intrepid Army of Northern Virginia.

For the rest of the year, that army would be bogged down in the Siege of Petersburg, marking a new phase of static trench warfare. Gone were the swift maneuverings and big bloody battles of the Overland Campaign; at Petersburg, each army would sit in its trenches, hoping to slowly bleed the other dry. Aside from its bloodshed, Cold Harbor therefore marked the end of one phase of the war, and the beginning of another.