It was supposed to be HBO’s next big thing: a high-concept drama from the creators of “Game of Thrones,” set in an alternate America where the Southern states seceded from the Union and slavery continued into the present day.
Instead, the new series, called “Confederate,” has provoked a passionate outcry from potential viewers who are calling out HBO and the creators over how they will handle this volatile mixture of race, politics and history. Several historians and cultural critics are also skeptical about whether the “Game of Thrones” team, David Benioff and D. B. Weiss, are the right people to address the subject and if it should be attempted at all.
“Confederate” arrives at a time when many minorities feel their civil rights are under siege, and when issues surrounding the Civil War and its legacy — the propriety of displaying Confederate flags; the relocations and razings of Confederate monuments — continue to confront Americans on an almost daily basis.
To its critics, the show’s promise to depict slavery as it might be practiced in modern times is perhaps the most worrisome element of “Confederate.” They say that slavery, a grave and longstanding scar on the national psyche, especially for black Americans, should not be trivialized for the sake of a fantasy TV series.
“Racial history in this country is a very open, sensitive wound,” said Dodai Stewart, the editor in chief of Fusion, a social-justice culture and news site.
“Nothing’s settled, nothing’s healed,” Ms. Stewart said. “I want to believe that this will be handled sensitively. But it’s an emotional subject, and for too many people it’s uncomfortably close to the reality they already experience.”
No scripts have been written and not a single frame has been shot for “Confederate,” which will not make its debut any sooner than next year. But the show’s pedigree is already established: With “Thrones,” Mr. Benioff and Mr. Weiss are responsible for HBO’s most-watched series ever and the winner of the Emmy Award for drama series for the past two years.
The show joins a television landscape in which alternate-history narratives are becoming increasingly popular, as seen in dystopian programs like Amazon’s “The Man in the High Castle” (adapted from the Philip K. Dick novel) and Hulu’s “The Handmaid’s Tale” (from the novel by Margaret Atwood).
In a news release announcing its acquisition of “Confederate,” HBO said the series would depict hypothetical events leading up to a “Third American Civil War,” and follow characters “on both sides of the Mason-Dixon Demilitarized Zone,” including “freedom fighters, slave hunters, politicians, abolitionists, journalists, the executives of a slaveholding conglomerate and the families of people in their thrall.”
While this subject matter is delicate in its own right, there is particular concern about how it will be handled by Mr. Benioff and Mr. Weiss.
In their time on “Game of Thrones,” they have been criticized for what some viewers regard as the routine and insensitive depiction of rape, and an overreliance on sexual violence as a plot device.
“Thrones” features few black actors in prominent roles, other than characters who are or once were slaves, and includes a plotline in which a population of darker-skinned slaves was liberated by a white savior.
Eric Foner, the Columbia University history professor and Pulitzer Prize-winning author of “The Fiery Trial: Abraham Lincoln and American Slavery,” expressed dismay when he heard that Mr. Weiss and Mr. Benioff were the creators of “Confederate.”
“‘Game of Thrones,” to me, is just an exercise in violence and sexual abuse, and many other things that draw a crowd but don’t have much redeeming social significance,” Mr. Foner said in a telephone interview.
He added: “I hope they know more about the American Civil War than they do about the medieval world.”
Mr. Weiss and Mr. Benioff have become two of the most important talents at HBO, which prides itself on creative freedom. . Under their guidance, “Game of Thrones” has become a ratings blockbuster, delivering 16.1 million viewers across multiple platforms for its Season 7 premiere Sunday.
As the show approaches its grand finale (no sooner than next year), a vital priority for HBO has been securing a new project from its creators.
The network declined to make Mr. Benioff and Mr. Weiss available for interviews. In the announcement for “Confederate,” they said they had been discussing the idea for several years and had considered pursuing it as a feature film before bringing it to HBO.
Mr. Weiss and Mr. Benioff said in the announcement that they would be working on “Confederate” with the husband-and-wife writer-producers Malcolm Spellman (“Empire”) and Nichelle Tramble Spellman (“The Good Wife”), who are black. Mr. Spellman, reached by phone on Thursday, declined to comment for this story.
Still, some performers have already suggested that they want no part of a series like “Confederate.” The actor David Harewood, a star of programs like “Supergirl,” “Homeland” and “The Night Manager,” wrote in a Twitter post, “Good luck finding black actors for this project.”
There is a longstanding tradition of historical fiction that has explored alternate depictions of the Civil War and its aftermath. Winston Churchill wrote a fanciful essay in 1930 entitled “If Lee Had Not Won the Battle of Gettysburg.”
In “C.S.A.: The Confederate States of America,” a mock documentary from 2004, the writer-director Kevin Willmott explored the imaginary history of a Confederacy that wins the Civil War and expands across the Western Hemisphere.
Mr. Willmott wrote in an email on Thursday that he had no comment, except to say that he and Spike Lee, his executive producer on the film, “will be speaking to our lawyer about the HBO project.”
But alternate history can also prove to be unexpectedly provocative. The marketing campaign for Amazon’s “The Man in the High Castle,” set in an America where the Axis powers won World War II, was condemned for its prolific use of German eagles, iron crosses and other fascist imagery.
The “Handmaid’s Tale” series, in which the United States has become a theocracy and women are subjugated, was criticized for eliding issues of race in its fictional society and featuring a largely white cast.
Still, both of these shows had their respected literary source material to fall back on and quell the preliminary concerns of viewers.
Gavriel D. Rosenfeld, a history professor at Fairfield University and the editor of a blog called The Counterfactual History Review, said that some alternate histories are bound to be more controversial than others; some eras have more clearly defined heroes and villains.
“Everyone agrees that we can hate the Nazis,” Mr. Rosenfeld said. “There’s no dispute there. The Civil War is still, 150 years later, an unmastered legacy in our country.”
Compared to fantasy stories like “Game of Thrones” or “Lord of the Rings,” Mr. Rosenfeld said that alternate history has a unique power to “prick our conscience and make us realize that history didn’t have to happen the way it did.”
“It forces us to confront that our world was not inevitable,” Mr. Rosenfeld said. “Either you’re going to imagine history turning out better or you’re going to imagine history turning out worse. Those are highly symbolic and reflective of people’s interpretations.”
He added: “Depending on your perspective, one can imagine a fantasy or a nightmare.”