A hard Mississippi rain fell Oct. 5, 1863. The Civil War had been grinding for 33 months and the Confederacy, just whipped in Vicksburg, had more to worry about than the descending Union troops.

Senior Confederate officer Amos McLemore had come down to the piney woods of Jones County, Miss., to deal with hundreds of Southern soldiers who had grown so weary of the bloodshed and incompetent leadership that they'd defected to fight the Confederacy from inside the deep South.

This surprising band of pro-Union Southerners and their leader, an antislavery farmer named Newton Knight, are the fascinating focal points of "The State of Jones." Written by Washington Post journalist Sally Jenkins and Harvard University history Prof. John Stauffer, the book fittingly combines crisp narrative with exhaustive historical context.

Knight's story takes a defining turn that rainy night when McLemore and his men, soaked from patrolling in the rain, stopped by a house in Ellisville, Miss. "Too muddy for the parlor, they moved into a bedroom, where the fire was built up as they shed their sodden broadcloth coats."

As the men surrounded the hearth, Knight and a young cousin crept up to the house and climbed a fence so they wouldn't cause the gate to creak. They drew broomstraws, but when young Alpheus Knight pulled the short one, Knight didn't trust his cousin's aim. So he eased into the mansion himself, kicked open the bedroom door and shot a hole through McLemore's chest.

"He'd crossed over, he was no longer a mere deserter but an enemy combatant," the authors write. "His transformation was surely the result of the awfulness of battle and the realization that he had more in common with the slaves he'd met in the swamps than the Confederate authorities who claimed to be his countrymen."

The book opens decades after this county of farmers virtually seceded from the secession. In 1921, with Knight well in his 90s, a Model T-driving reporter visits his cabin.

"The Civil War's over long ago," Knight tells him. "No use stirring up that old quarrel this late date, is there?"

There are plenty of reasons to stir it up. We learn about Knight's conscription, his swampy hideouts, his two-year insurrection against the Confederacy and his two families -- one black and one white. We watch him change. Jenkins and Stauffer succeed in telling the complex history of the Civil War, and its disastrous Reconstruction aftermath, through the steely eyes of this crusty old man.

To some, Knight was a hero who built a school for freed blacks after the war, only to see it burned down. To others, he was a traitor and murderer.

"Newton Knight remained one of the less known and poorly understood warriors of the Civil War," they write. "An expert in the art of disappearance, he had faded into the weeds of time the way he once faded into the canebreak of the Mississippi Piney Woods."

Their book dusts off an obscure Mississippi soldier and his improbable battle, flushing him from the swamp of history better than all those bloodhounds ever did.

Curt Brown, a Star Tribune reporter, is also the author of "So Terrible a Storm," a nonfiction account of a 1905 storm that smacked Duluth.