June 17 was a day of disjointed, piecemeal attacks: Union force thrown at the line in uncoordinated pieces instead of one weight, and ground up for it. At dawn, brigades of Brigadier General Robert B. Potter’s (North) IX Corps lunged forward and did well at first, capturing nearly a mile of works and some 600 prisoners, before stalling against a second Confederate line under enfilade fire (fire raking down the length of their line from the flank, the deadliest angle there is). Around two in the afternoon Brigadier General John F. Hartranft’s (North) brigade went forward at a bad angle and was flanked and stopped. In the evening Brigadier General James H. Ledlie’s (North) division attacked and failed. Ledlie, the account flatly records, was observed to be drunk during the fight, the same incompetence that would help wreck the Battle of the Crater on this same ground two months later.

That night Beauregard (South) did again what he had done before: he traded ground for strength. He withdrew his men about a mile west to a fresh line his engineers had laid along Taylor’s Branch, a creek running to the Appomattox, a shorter and stronger position. And finally Lee moved. The proof he had been waiting for came when his son, Major General W.H.F. “Rooney” Lee (South), confirmed that Grant’s army really had crossed the James. Convinced at last where the whole Union army had gone, Lee dispatched two divisions toward Petersburg, marching beginning at three in the morning on June 18.

On June 18 the Union did not know the door had already closed. At dawn, the II Corps (Hancock now incapacitated by his unhealed Gettysburg wound, with Major General David B. Birney (North) taking command) and the XVIII Corps rushed forward into the old Dimmock works, only to find them empty: Beauregard had pulled back in the night. The advance then slammed into the new line at Taylor’s Branch and halted under heavy fire. By midday Lee’s lead divisions reached the field, giving Beauregard over 20,000 men, and Grant, now with perhaps 67,000 across the front, was looking at exactly the thing Cold Harbor had taught him to dread: defenders dug in, in strength, behind earthworks. Cold Harbor was the massacre two weeks back that had started all of this, the day a frontal charge cost thousands in minutes for nothing. He ordered the charge anyway.

It was a slaughter. The noon attacks broke against the works. Brigadier General Orlando B. Willcox’s (North) division came out of its charge with only about 1,000 men still standing. Major General Gouverneur K. Warren’s (North) V Corps was stopped cold by murderous fire from Rives’s Salient. A salient is an outward bulge in a defensive line, which is exactly what made this one so deadly: the strongpoint at Battery 27, where the line jutted out across the Jerusalem Plank Road, could pour fire onto attackers from the front and both sides at once. Among the wounded there was Colonel Joshua L. Chamberlain (North), already famous from Gettysburg, shot through at the salient with a wound everyone thought mortal. He survived, and Grant promoted him brigadier general on the field.

And then, at 6:30 that evening, came the worst of it.

The 1st Maine Heavy Artillery (North) had spent the war until recently as garrison troops, manning the fixed defenses of Washington, about 900 men who had never made a charge. Now they were infantry, and they were ordered forward across open ground against works that could not be carried. They went. In a matter of minutes they lost 632 men, the heaviest single-battle loss of any regiment in the entire war. A regiment is a few hundred to a thousand men. This one was effectively annihilated in the time it takes to read this page. That is the image the four days end on: converted garrison soldiers obliterated against a wall, because by then there was no longer any way over it.

After that, Grant called off the frontal assaults. Across the four days the Union had lost roughly 11,000 men, about 11,386, with the killed near 1,700, against Confederate losses in the range of 3,200 to 4,000: the attackers had bled roughly three times what the defenders did, the signature price of throwing infantry against entrenchments. Major General George G. Meade (North), who had been running the assaults, saw what was coming. In a letter home he judged that the army would have to settle in for a siege of Petersburg before it could even begin a siege of Richmond, and his official report after June 18 carried a line of plain regret.

“It is a source of great regret that I am not able to report more success.”

Major General George G. Meade (North)

And so the Siege of Petersburg began: surround the city and starve it out rather than storm it, because the open-field assault had failed and there was nothing else left to try. It would run for nine and a half months of trench warfare, the longest siege of the war, ending only with the Union breakthrough of April 2, 1865, the fall of Richmond, and Lee’s surrender at Appomattox on April 9. The pivot from open-field war to trench war in the East happened right here, in these four days.