Why roughly twenty thousand men charged two miles of open field into a wall of dug-in guns at dusk begins the night before, on a road in the dark, where an entire Union army walked right past the Confederates who had come to trap it.

In September 1864, Atlanta fell to the Union army of Major General William T. Sherman. The Confederate Army of Tennessee, one of the South’s two great field armies, had failed to hold it, and its commander, Lieutenant General John Bell Hood (South), made a long shot dressed up as a strategy. Rather than chase Sherman (who was, in fact, about to turn the other way and march for the sea), Hood drove his army north, gambling that an invasion of Tennessee and a threat toward the Ohio River might pull Sherman back, rally a sagging cause, and win back ground the South had lost.

The shot only worked if Hood could catch and destroy the Union force in his path before it reached safety. That force belonged to Major General John M. Schofield (North), about twenty-seven thousand men, built out of his own small army plus an attached corps (a corps being a major chunk of an army, tens of thousands of men under one general). Schofield was falling back north toward Nashville, where Major General George H. Thomas (North) was concentrating roughly twenty-five thousand more Federals behind heavy fortifications. The arithmetic was brutal for Hood. If Schofield and Thomas joined up inside the Nashville works, his already outnumbered army had no realistic road to victory. He had to smash Schofield in the open, alone, before the two halves of the Union force became one.

On November 29 he very nearly did. Hood out-marched Schofield, peeling most of his army off on a flanking march, crossing the Duck River east of the town of Columbia (the place Schofield was retreating from, just south of here), and by nightfall Confederate troops had reached the Columbia Pike at Spring Hill: the exact road Schofield’s army had to use to retreat north. A flanking march, here, means swinging wide around an enemy’s side instead of hitting him head-on. Hood had swung wide and landed behind his quarry, astride its only escape route. On paper, Schofield was trapped.

And then he wasn’t. Through a cascade of command failures that night (disputed orders, confusion in the dark, and Hood’s own premature confidence that the Union army was already bottled up) the Confederates never closed the road and never attacked. All through the night of November 29 and 30, Schofield’s entire army and its wagon train marched up the Columbia Pike and slipped past, in some accounts close enough to the sleeping Confederate camps to see their fires. Nobody stopped them. By dawn, Schofield had reached the town of Franklin, about twelve miles north, and put his men to digging in, throwing up dirt walls to fight behind.

Hood woke up to find his prey gone. The American Battlefield Trust describes him that morning as “wrathy as a rattlesnake,” accusing his own army of cowardice. What he did next, and why, is one of the war’s genuine historical arguments. Many historians read the assault Hood was about to order as an act of fury and humiliation, a punitive charge aimed at the army he blamed for Spring Hill. Hood himself gave a colder, strategic reason: with Schofield this close to the safety of Nashville and no distance left to flank him again, Hood decided to make one more attempt to overtake and destroy the Union army before it got behind its walls. Both readings survive in the sources. What is not in dispute is what the decision produced.