Here is the situation Robert E. Lee woke up to on the first of May: a Union army of perhaps 130,000 men had gotten behind him, a second Union force was pressing his front at Fredericksburg, and his own army numbered around 60,000 all told. The textbook answer to being outnumbered two to one, with enemies on two sides, is to retreat and save the army. Lee did the opposite, twice, in a way that has been studied by soldiers ever since as either reckless or perfect, and possibly both.

The first thing that saved him was that Major General Joseph Hooker (North) flinched. On May 1, Union columns pushed east out of the Wilderness toward the open ground where their numbers and their guns would finally count. Lee’s lead elements, with Lieutenant General Thomas "Stonewall" Jackson (South) driving them forward, met that advance and pushed back. The fighting was sharp but not decisive, and by every measure Hooker still held the advantage. Then Hooker ordered his men to stop and pull back into the Wilderness, surrendering the open ground he had marched all that way to reach. Major General Darius Couch (North), his senior subordinate, came away from that order shaken; he later wrote that he left Hooker’s presence "with the belief that my commanding general was a whipped man." The battle had been fought for one afternoon, and already the psychology had flipped: the bigger army was digging in to defend, and the smaller army was coming on.

With Hooker hunkered down, Lee did the first audacious thing. He split his army in front of a superior enemy. He left a small holding force of somewhere between 9,000 and 11,000 men under Major General Jubal Early (South) to watch Fredericksburg and hold off Sedgwick, and took everyone else west to deal with Hooker. That alone would have been bold. What he and Jackson decided to do next was, by the standards of military prudence, close to insane.

What made it possible was a piece of intelligence that arrived that night. Major General J.E.B. "Jeb" Stuart (South), Lee’s cavalry chief, rode in with a report from his scouts under Brigadier General Fitzhugh Lee (South), Robert E. Lee’s own nephew, who had ridden out along the Union line and found its far western end hanging open. Hooker’s right flank, out past the XI Corps, was unanchored: it leaned on no river, no hill, no obstacle of any kind, the soldier’s nightmare condition called being "in the air," a flank with nothing to lean on and nothing to stop an enemy from getting around the end of it. Lee and Jackson did not intuit the weak spot. Their cavalry found it for them, and handed them the whole battle.

That night, the two men sat on cracker boxes by a fire in the woods and worked out a plan to split the army again. If a force could march clear around the Union army through the concealing Wilderness and come in on that exposed flank from the side, it could roll the whole line up like a carpet. The catch was the size of the force required and the distance it would have to travel. Jackson proposed taking his entire Second Corps, around 28,000 to 30,000 men, on a march of roughly twelve miles around the Union army’s front.

The arithmetic is staggering. Lee was already outnumbered better than two to one. He had just peeled off a third of what remained to hold Fredericksburg. Now he proposed to send the larger part of what was left on a half-day march around the enemy, leaving himself with perhaps 14,000 men directly in front of Hooker’s 70,000-odd. If Hooker attacked the thin force in front of him during those hours, Lee’s army would simply cease to exist.

The road existed because the country knew it and the army did not. Jackson’s mapmaker, Jedediah Hotchkiss (South), the topographer whose careful maps were one of the Confederacy’s quiet advantages, was shown a concealed route by Charles C. Wellford, the proprietor of an iron furnace called Catharine Furnace south of the crossroads, who knew the local roads the way only a man who hauls iron over them can. That hidden road, looping south and west out of sight of the Union lines, was the whole plan. Without it there is no flank march and no surprise. Lee bet his army on a furnace owner’s knowledge of his own back roads.

Lee chose, twice in two days, the single riskiest option available to a general: dividing his force in the face of a stronger enemy, the textbook recipe for being beaten in detail (destroyed one piece at a time). He got away with it twice in forty-eight hours, partly because his subordinates were good enough to execute it, and largely because the man across the field had already decided he was beaten.