Whatever the terms of Gen. Robert E. Lee’s surrender to General Grant at Appomattox, the Confederacy didn’t die in April 1865; it simply morphed. Frederick Douglass put it this way in 1894 in “Lessons of the Hour,” his last major speech: “The cause lost in the war is the cause regained in peace, and the cause gained in peace is the cause lost in war.” Redemption was “the defeat of emancipation,” he continued, “the determination of slavery to perpetuate itself, if not under one form, then under another,” and, he added, “the folly of endeavoring to retain the new wine of liberty in the old bottles of slavery.”

Those “old bottles” of the dawning Jim Crow era included the development of sharecropping and the nefarious convict lease system, to which we can trace the roots of mass black incarceration; the lynching of more than 4,000 black people by 1950, according to Bryan Stevenson’s Equal Justice Initiative; segregation in public places and in every field of opportunity; and a brilliantly executed propaganda campaign that successfully changed the narrative of the cause of the Civil War from freeing the slaves to preserving states’ rights and a people’s noble way of life, the so-called Lost Cause.

Central to that propaganda campaign was the proliferation of an ocean of images of black people as subhuman, as well as what was in effect our country’s first culture war. It was masterfully executed by Mildred Lewis Rutherford, the “historian general” of the United Daughters of the Confederacy, who published a textbook “measuring rod” to verify that any account of the Civil War or Reconstruction fell within the “proper” guidelines. Not only were black achievements of Reconstruction to be undone; even their memory was so dangerous that it, too, had to be edited and erased.

So urgent was the rollback of Reconstruction that it became the subject of Hollywood’s first blockbuster movie, D.W. Griffith’s “The Birth of a Nation,” a silent film that silenced the truth. We tend to think of it as a defense of slavery, but it was actually a radically racist critique of black achievement during Reconstruction, especially of black lawmakers, who were the living embodiment of the Reconstruction amendments — in particular the 14th, with its promise of birthright citizenship, which President Trump dreams of undoing. Rutherford on her front and Griffith on his sought to fulfill the mission of Redemption, and succeeded: to memorialize the Old South in the new mythology of the Lost Cause — indeed, to make America great again. Out of this movement to take control of the narrative came the Confederate monuments that have been generating such heated debate in recent years, particularly since President Trump took office, barking out a narrative frighteningly similar to that of Redemption.

J ust over a month before Martin Luther King Jr. was assassinated in 1968, in a speech at New York’s Carnegie Hall commemorating the centenary of the birth of W.E.B. Du Bois and the significance of Du Bois’s own defiant defense of what he called “Black Reconstruction,” he paused to reflect on the lasting impact of the Redemptionist narrative about “the Negro’s role in the Reconstruction years.” Where Du Bois had implored the freedmen to “fight against ridicule and monstrous caricature, against every refinement of cruelty and gross insult,” King, too, sought to make his audience see that “it was a conscious and deliberate manipulation of history and the stakes were high.” If “Negroes wallowed in corruption, opportunism, displayed spectacular stupidity, were wanton, evil and ignorant, their case was made. They would have proved that freedom was dangerous in the hands of inferior beings.” The hideous, lingering result was that “the collective mind of America became poisoned with racism and stunted with myths.”

The story of the Redemptionist overthrow of Reconstruction shatters all notions that history is a straight line drawn inexorably toward progress, and in that shattering there is a lesson for us all: vigilance. Perhaps the most surprising fact about Reconstruction is that its rollback has lasted far longer than Reconstruction itself, and it continues to this day. President Barack Obama’s eight years in office unleashed tremendous racial resentment and fear, capitalized upon shamelessly first by Mr. Trump’s 2016 campaign and then, mercilessly and unendingly, in his presidency. We can count on Mr. Trump to outdo himself in his campaign for a second term. As we look to resist this Neo-Redemption era, we owe it to ourselves and our children to study again and again the history of the rise and fall of Reconstruction, because the problems that emerged after the Civil War have never been adequately resolved. And the South’s Redemption teaches us that achievements thought to be permanent and lasting — including the Reconstruction amendments themselves — can be diminished and even demolished.

“Strange things have happened of late and are still happening,” Douglass himself worried aloud in that last major speech of his. More than 200 years after his birth, I can’t help wondering what he’d say about the current state of affairs in our democracy. Horrified by the scourge of lynching a generation on from what was supposed to have been a “new birth of freedom” for black and white Americans, Douglass, in surveying the devastating shadows cast over the final years of his life, said that “some of these” developments “tend to dim the luster of the American name, and chill the hopes once entertained for the cause of American liberty.” He continued: “When the moral sense of a nation begins to decline and the wheel of progress to roll backward, there is no telling how low the one will fall or where the other may stop. The downward tendency already manifest has swept away some of the most important safeguards.”

And then he posed a question still haunting us today: “What’s next?”