NEW YORK >> From the time it aired nearly 30 years ago, Ken Burns’ Civil War documentary has been a popular sensation and subject of debate.

The 11-hour, nine-part series premiered in September 1990 and became one of PBS’ most widely seen educational programs, with some 40 million taking in at least part of the original broadcast. “The Civil War” was the rare documentary to inspire a skit on “Saturday Night Live” and helped make Burns, in his mid-30s at the time, the rare documentary maker recognizable to the general public.

During its initial run, then-President George H.W. Bush and Gen. Norman Schwarzkopf, who would soon command the U.S.-led Gulf War, were among those who watched it. Earlier this week, White House Press Secretary Sarah Huckabee Sanders cited the film in defense of Chief of Staff John F. Kelly, who had said the Civil War could have been avoided with more compromise.

“I don’t know that I’m going to get into debating the Civil War, but I do know that many historians, including Shelby Foote in Ken Burns’ famous Civil War documentary, agree that a failure to compromise was a cause of the Civil War,” Sanders said. “There are a lot of historians that think that.”

And a lot of historians who don’t.

“There’s no one who thinks intransigence was shared equally,” says historian Harold Holzer. “Kelly accepted the old line idea that people were just arguing about tariffs and states’ rights.”

Burns himself challenged Sanders’ interpretation on Twitter. He wrote that “Many factors contributed to the Civil War. One caused it: slavery.” He noted that the documentary ends with commentary from Barbara Fields, a revered scholar of slavery and the Civil War, who says “the Civil War is still going on. It’s still to be fought and regrettably it can still be lost.”

As much as any book or film in recent years, Burns’ series has shaped how Americans perceive the war. Holzer says “The Civil War” has a couple of important and productive legacies — it brought slavery to the center of the Civil War debate, erasing some of the damage caused by “Gone With the Wind” and other narratives of the past, and helped create an enduring popular following for Civil War stories. But he says “The Civil War” was “somewhat romanticized,” notably in its treatment of Gen. Robert E. Lee and other Confederate leaders.

“Since the film and book appeared there’s been a lot very good work done on Robert E. Lee,” says historian Geoffrey Ward, who has collaborated with Burns on “The Civil War” and numerous other projects. “Had I the benefit of it all I’m sure we would have painted a harsher but more accurate portrait of Lee.”

Sanders’ comments do reflect what Foote said in the film: Scholars argue about the documentary in part because Burns included commentators with very different interpretations. Fields’ perspective — that slavery was the cause, that the conflict was necessary and unavoidable and that initial hopes for black equality were fiercely resisted in the South and remain unmet — is common among historians now. But far more time in “The Civil War” is given to Foote, who died in 2005. Foote was a popular Southern historian and raconteur who scorned slave holders and abolitionists, and in Burns’ film contended that the war happened “because we failed to do the thing we really have a genius for, which is compromise.”

Ward praised Foote as a “master storyteller” but added that “his views on its causes were his own.” The cause of the war, Ward added, was slavery.

“Ken Burns always looks for varied voices and he always looks for characters, and Shelby Foote was certainly a character,” Holzer says. “The most amazing thing he said was that the two great geniuses of the war were Lincoln and (Confederate Gen.) Nathan Bedford Forrest. Foote somehow compared the great emancipator with a man who owned slaves, murdered blacks and joined the Ku Klux Klan. ” The documentary inspired enough discussion to become a book, “Ken Burns’ The Civil War: Historians Respond,” a 1995 publication featuring contributions by such leading scholars as C. Vann Woodward and Eric Foner and responses from Burns and Ward.

The commentary ranges from praise by Woodward, a Pulitzer Prize winner and consultant for the film, for Burns thoroughness and dedication, to negative critiques by Foner and others. Catherine Clinton, who has worked on numerous books about the South, faulted the “wholesale neglect of women.” Slavery historian Leon Litwack alleged that the film “revives the pernicious notion” that the “war need not happened at all.” Foner, an authority on Reconstruction, criticized Burns for making “no attempt to convey the state of the nation at war’s end in 1865.”

“The word ‘Reconstruction’ is never mentioned, and what little information there is about the era is random and misleading,” Foner wrote.

In the book, Ward acknowledged mistakes, including the wrong date for Lincoln’s assassination (he had confused the date in April with the day of Franklin Roosevelt died in 1945). But he disputed the comments of Foner and others and noted that he and Burns had done their best within the boundaries of the medium, writing that “Television is better at narrative than analysis, better at evoking emotions than at expounding complex ideas.”

Burns, in the book’s final essay, wrote that he and his collaborators had worked hard to “question assumptions” and “doubt easy solutions.” He consulted Confederate historians, Marxist historians and those in between. The film, he insisted, was not meant to be a definitive statement and had no set agenda, beyond the evil of slavery and the timidity of Union Gen. George C. McClellan.

“The rest of the war, North and South, male and female, black and white, civilian and military, was a vast and complicated drama,” he wrote, “poetic as well as social in dimension, emotional as well as didactic in context and scope, instructive to the heart as well as the head.”