Five Forks did in an afternoon what nine and a half months of siege had not: it cracked the whole position open. With the last railroad cut and the right flank caved in, the Petersburg line could not be held a day longer, and Grant knew it. He ordered a general assault for the dawn of April 2, and all along the front the Union army went forward against trenches stretched too thin to stop them. The lines broke. Lieutenant General A. P. Hill (South), one of Lee’s longest-serving corps commanders, was killed that morning trying to reach his men.

That was the day the dam gave way. Robert E. Lee, his front broken in a dozen places, sent word to Richmond that the capital and Petersburg both had to be abandoned at once. The message reached Jefferson Davis in church on a Sunday morning, and by nightfall the Confederate government was fleeing south and Richmond was burning, set alight by its own retreating troops. After almost four years and a ring of forts that had held since the summer before, the two cities the whole Eastern war had been fought over were gone in a single day.

What followed was a footrace. Lee got the remnant of his army out to the west, hoping to swing south and join the last Confederate army still in the field in North Carolina, and Grant set out after him with Sheridan’s cavalry slashing at the head and flanks of the retreat. There was no food at the end of the road and very little hope. Hungry, outnumbered, and outrun, Lee’s men marched and fought westward for a week with the Union army closing around them like a fist.

It ended at a village called Appomattox Court House, about eighty-five miles west of Five Forks. On April 9, with Sheridan’s cavalry across the road in front of him and Union infantry coming up behind, Lee found his way blocked and his army down to a starving fraction of its old strength. He sent forward a flag of truce, and that afternoon he met Grant in the parlor of a private home and surrendered the Army of Northern Virginia. The war in Virginia was over. Other armies would lay down their arms in the weeks that followed, but the surrender at Appomattox is the moment the country has always counted as the end.

It is worth being plain about what ended. The Confederacy had been founded to preserve and extend slavery, and the army that surrendered at Appomattox had spent four years fighting to keep four million people in bondage. When that army gave up its weapons, the institution it had defended died with it. Five Forks does not have the fame of Gettysburg or the horror of Antietam, but it was the blow that started the last week of the war, and the last week of slavery in the United States.