The American Civil War has been combed over in popular culture countless times, but the true story that inspired the new film Free State of Jones, out Friday, may still surprise some viewers. It's not the kind of thing commonly taught in textbooks: the story of Newton "Newt" Knight (played by Matthew McConaughey in the film), a man who, when the South seceded, seceded right back. He and his fellow "Southern Yankees"—both black and white—tried to start their own pro-Union "free state" in Jones County, Miss.
If you haven't heard about Knight before, there may be a very particular reason. Jim Kelly, a local historian who is a descendent of Newton Knight's and consulted on the film, argues that the story of Knight—like the stories of many other white Southerners who rejected the Confederacy—was deliberately erased.
As Kelly explains, even as he researched and taught history in the very area that had once held the "free state," the tales he heard about Newton Knight all followed one narrative: Knight was a terrible person, so bad he wasn't worth thinking about. But the word about Knight was so bad that Kelly figured it couldn't possibly be right. "I noticed that so many different writers all said the same story, almost verbatim, to the point where it was a red flag," he says. "Being trained as a historian, that struck me. [That means] there's more here than we're aware of."
About a decade ago, he revisited the topic—and found that he was right.
After the post-Civil War Reconstruction period, which ended in the mid-1870s, those in power in the South led a sweeping effort to return the balance of power to the political and racial elites who had held sway before the war. During that time, Kelly says, Southern Democrats won "the victor's right to history"—and Northern politicians were eager to put the past behind them, too. The result was that stories that didn't conform to the version of the Civil War preferred by those in power were hidden. Naturally, those taboo stories would include anything about Southerners being divided about slavery and secession. The effort to highlight only positive stories about slavery and the Confederacy was particularly urgent for those who had held high ranks in the secessionist forces and feared they might be executed for treason if the North didn't see things their way. After a generation or two of "selective memory," stories like that can begin to sound like the truth, Kelly says.
"The propaganda job was so effective," Kelly says. "[Knight's] memory was buried to uphold the lost-cause mythology of the war."
Today, Kelly describes Knight as an American patriot who "didn't go with the program as far as race was concerned"—especially in his choice to marry his wife Rachel, a former slave.
There's proof in TIME's own archives that the echoes of Knight's story passed all the way down to, as the magazine put it, "the children's children." In 1948, an article told the story of Davis Knight and Junie Lee Spradley, a young married couple living in Mississippi who had been shocked when he was arrested for the crime of interracial marriage:
Knight said they were wrong. But a relative, irked by an old family feud, had dug up Davis Knight's genealogy. His great-grandfather had been Cap'n Newt Knight , who deserted the Confederate Army and set up "The Free State of Jones" in Jones County. Cap'n Newt had had children by Rachel, a Negro slave girl. Rachel was Davis Knight's great-grandmother.
Through succeeding generations the Knights had married white men or women. Davis Knight's own parents had not known of the Negro strain in their ancestry. The story the relative dug up would affect a number of other families in the neighborhood, all sprung from the loins of Cap'n Newt and Rachel. Last week a court in Ellisville convicted Cap'n Newt's great-grandson of miscegenation, sentenced him to five years in jail.