We pause here to note that wars are complex events whose causes can never be adequately summed up in a phrase, that they can start out as one thing and evolve into another, and that what people think they are fighting for isn’t always the cause history will record. Yet, as Lincoln noted in his second inaugural address, there was never any doubt that the billions of dollars in property represented by the South’s roughly four million slaves was somehow at the root of everything, and on this point scholars who don’t agree about much of anything else have long found common ground. “No respected historian has argued for decades that the Civil War was fought over tariffs, that abolitionists were mere hypocrites, or that only constitutional concerns drove secessionists,” writes University of Virginia historian Edward Ayers. Yet there’s a vast chasm between this long-established scholarly consensus and the views of millions of presumably educated Americans, who hold to a theory that relegates slavery to, at best, incidental status. How did this happen?

One reason boils down to simple convenience—for white people, that is. In his 2002 book “Race and Reunion,” Yale historian David Blight describes a national fervor for “reconciliation” that began in the 1880s and lasted through the end of World War I, fueled in large part by the South’s desire to attract industry, Northern investors’ desire to make money, and the desire of white people everywhere to push “the Negro question” aside. In the process, the real causes of the war were swept under the rug, the better to facilitate economic partnerships and sentimental reunions of Civil War veterans.

But an equally important reason was a vigorous, sustained effort by Southerners to literally rewrite history—and among the most ardent revisionists were a group of respectable white Southern matrons known as the United Daughters of the Confederacy.

The UDC sounds like one of those genteel ladies’ organizations that would have quietly passed into oblivion about the time women ditched their girdles and entered the labor market, but they are still around—a group of about twenty thousand ladies dedicated to various educational and historical preservation causes. Since 1955, the UDC has recruited next-generation members through a young persons’ auxiliary called the Children of the Confederacy, which does similar kinds of work. Blight was surprised when I told him in an e-mail that as part of my research I planned to visit the 2008 C of C convention in Fredericksburg, Virginia. “I knew there used to be such an [auxiliary] organization decades ago but did not know that it still exists,” he replied. “Amazing. How I would like to be a fly on the wall there.”

The significance of the UDC lies not in its present-day clout, which is negligible, but in its lasting contributions to history— both for good and for ill. From its inception in 1894 up through the 1960s, the UDC was the South’s premier social and philanthropic organization, an exclusive social club where the wives, sisters, and daughters of the South’s ruling white elite gathered to “revere the memory of those heroes in gray and to honor that unswerving devotion to principle which has made the confederate soldier the most majestic in history,” as cofounder Caroline Meriwether Goodlett grandly put it. At first, the UDC provided financial assistance and housing to veterans and their widows, offering a vital public service at a time when for all practical purposes most local and state governments in the South were nonfunctional and/or broke. Later, as the veteran population aged, the UDC built homes that allowed indigent veterans and their widows to live out their days with some measure of dignity. Long before there was such a thing as the National Park Service, the UDC played a crucial role in preserving priceless historic sites, war cemeteries, and battlefields across the South. At the same time, it embarked on a spree of monument building: most of those confederate monuments you can still find in hundreds of courthouse squares in small towns across the South were put there by the local UDC chapter during the early 1900s. In its way, the UDC groomed a generation of Southern women for participation in the political process: presidents attended its national convocations, and its voice was heard in the corridors of the U.S. Capitol.

But the UDC’s most important and lasting contribution was in shaping the public perceptions of the war, an effort that was begun shortly after the war by a Confederate veterans’ group called the United Confederate Veterans (which later became the Sons of Confederate Veterans—also still around, and thirty thousand members strong). The central article of faith in this effort was that the South had not fought to preserve slavery, and that this false accusation was an effort to smear the reputation of the South’s gallant leaders. In the early years of the twentieth century the main spokesperson for this point of view was a formidable Athens, Georgia, school principal named Mildred Lewis Rutherford (or Miss Milly, as she is known to UDC members), who traveled the South speaking, organizing essay contests, and soliciting oral histories of the war from veterans, seeking the vindication of the lost cause “with a political fervor that would rival the ministry of propaganda in any 20th century dictatorship,” Blight writes.

Miss Milly’s burning passion was ensuring that Southern youngsters learned the “correct” version of what the war was all about and why it had happened—a version carefully vetted to exclude “lies” and “distortions” perpetrated by anti-Southern textbook authors. To that end, in 1920 she wrote a book entitled “The Truths of History”—a compendium of cherry-picked facts, friendly opinions, and quotes taken out of context, sprinkled with nuggets of information history books have often found convenient to ignore. Among other things, “The Truths of History” asserts that Abraham Lincoln was a mediocre intellect, that the South’s interest in expanding slavery to Western states was its benevolent desire to acquire territory for the slaves it planned to free, and that the Ku Klux Klan was a peaceful group whose only goal was maintaining public order. One of Rutherford’s “authorities” on slavery was British writer William Makepeace Thackeray, who visited Richmond on a tour of the Southern states during the 1850s and sent home a buoyant description of the slaves who attended him: “So free, so happy! I saw them dressed on Sunday in their Sunday best—far better dressed than English tenants of the working class are in their holiday attire.”

But presenting the “correct” version of history was only half the battle; the other half was preventing “incorrect” versions from ever infiltrating Southern schools. Before the Civil War, education was strictly a private and/or local affair. After the Civil War, it became a subject of federal interest. The first federal agency devoted to education was authorized by President Ulysses S. Grant in 1867, and Congress passed several laws in the 1870s aimed at establishing a national education system. White Southerners reacted to all this with a renewed determination to prevent outsiders from maligning the reputation of their gallant fighting men by writing textbooks especially for Southern students. One postwar author was none other than Alexander Stephens, former vice president of the Confederacy, whose portrayal of the war sounds remarkably like the version you hear from many Southerners and political conservatives today: it was a noble but doomed effort on the part of the South to preserve self-government against federal intrusion, and it had little to do with slavery. (This was the same Alexander Stephens who had proclaimed in 1861 that slavery was the “cornerstone” of Southern society and “the immediate cause of the late rupture and present revolution.”)

As the UDC gained in political clout, its members lobbied legislatures in Texas, Mississippi, North and South Carolina, and Florida to ban the purchase of textbooks that portrayed the South in anything less than heroic terms, or that contradicted any of the lost cause’s basic assertions. Its reach extended not just to public schools but to tenured academia—a little-known chapter of its propaganda effort is detailed by James Cobb in his 2005 book “Away Down South: A History of Southern Identity.” Cobb recounts how in 1911, for instance, University of Florida history professor Enoch Banks wrote an essay for the New York Independent suggesting that slavery was the cause of secession; Banks was forced by the ensuing public outcry to resign. Perhaps Banks should have seen that coming: seven years earlier, William E. Dodd, a history professor at Virginia’s Randolph-Macon College, had complained that to merely suggest the confederacy might not have been a noble enterprise led by lofty-minded statesmen “is to invite not only criticism but enforced resignation.” Dodd himself would later migrate to the University of Chicago, where he established a Northern outpost for Southerners who were interested in a serious examination of Southern history. Such scholarship was not encouraged back home: the first postwar society of Southern historians was created in 1869 for the explicit purpose of vindicating the confederate cause.

The fear of losing one’s job worked to keep most dissenters in line, but if that failed, self-appointed censors in the community were always on the lookout. In 1913, for instance, the sons of confederate Veterans succeeded in banning from the University of Texas history curriculum a book that they felt offered an excessively New England slant on recent history. The UDC industriously compiled lists of textbooks used in schools across the South, sorting them into one of three categories: texts written by Northerners and blatantly unfair to the South; texts that were “apparently fair” but were still suspect because they were written by Northerners; and works by Southern writers. Outside academia, the New South creed, popularized by Atlanta newspaper editor Henry Grady in an effort to spur economic development, also reinforced this new orthodoxy. A big part of Grady’s canny public relations was to pay extravagant homage to the imagined splendor of the antebellum South, and to portray the New South as a revival of that genius instead of what it really was: the rise of a whole new class of plutocrats.

If all of this wasn’t enough to stifle all public debate and intellectual inquiry in the decades after the war, other prevailing conditions might have finished the job: the widespread poverty of those decades, the rise of Jim Crow and the need to maintain the belief in white supremacy, a pervasive religious mindset that put a higher value on faith than on reason. There were more thoughtful voices, of course—in Atlanta, W. E. B. Du Bois was writing brilliantly about the black experience and reconstruction. But the racism of his day postponed his wider influence to a later era. For all but the rich and/or socially elite this was the South that H. L. Mencken lampooned as “a stupendous region of worn-out farms, shoddy cities and paralyzed cerebrums”—far more concerned with the next meal than with intellectual inquiry. Among white Southerners, rich or poor, the universally accepted history was the version that would later find fame in Margaret Mitchell’s 1936 novel “Gone With the Wind”—a book that sold millions, was translated into twenty-seven languages, and has probably had a more lasting influence on public perceptions about the South to this day than any other single work. It’s no wonder that the so-called Southern renaissance of the 1930s happened outside academia, in the field of fiction; as Cobb points out, the people least interested in understanding Southern history at that time were Southern historians, and Blight agrees. “It would have been impossible to grow up in the South from 1890 to World War I and not have heard or read [the lost cause version of history] many times over as the common sense of white Southern self-understanding.”

I would quibble with that last part; the era when this was “the common sense of white Southern self-understanding” lasted at least until 1960, very conservatively speaking, and its legacy thrives to this day. In an era when any assertion of “fact” is met by noisy counterassertions of competing “facts,” it’s hard to grasp how completely this warped version of history was accepted as gospel in the South, as silly to dispute as the law of gravity. Former New York Times correspondent John Herbers is an old man now, living in retirement in Bethesda, Maryland, with his wife, Betty. but when he was growing up in Mississippi in the 1930s and 1940s, “the lost cause was one of the main themes my grandmother used to talk about: ‘slavery was nothing to do with the Civil War—we had a cotton economy and [the North] wanted to dominate us.’ It was an undisputed topic.” At the time, he accepted this version, as children do; today, he is struck by the vigilance with which adults in his world implanted this story in the minds of their children. “They pushed themselves to believe that,” he said. “If [the war] had anything to do with slavery, they had no ground to stand on.”

Claude Sitton, another Southerner who covered the civil rights movement for the New York Times, remembers participating in a yearly essay contest sponsored by the UDC when he was a high school student in Rockdale County, Georgia, in the early 1950s. I did not encounter the UDC essay contests when I was a student in public schools in the 1960s, but the things I heard from my mother could have come straight from Miss Milly’s approved textbooks. History books were unfair to the South, she told me, so I was not to believe anti-Southern things I might read in them, and she was vigilant about correcting me if she heard me use the term “the Civil War” in conversation. To call it a Civil War was to concede that secession was impossible and/or unconstitutional—something no self-respecting Southerner should ever do. “The proper name,” she would say, “is The War Between the States.” Her reminder to me was nothing out of the ordinary; millions of Southern schoolchildren of my generation had absorbed such messages, as had several generations before us. “As late as the 1970s, neither textbooks nor curricula veered far from lost cause interpretations, especially in the Deep South,” writes historian Karen L. Cox—and in his book on the civil rights era in Mississippi, historian John Dittmer concluded that the lost cause version of post-Civil War reconstruction in the South still held sway among the vast majority of whites in that state as recently as the early 1990s.

Die-hard defenders of some version of the Lost Cause today say that the South has always been the victim of “political correctness” in school textbooks, and that this continues to this day. The truth is just the opposite: for decades, publishers of school textbooks went out of their way not to offend delicate Southern sensibilities in their treatment of the Civil War. One longtime publishing executive told me that when he got into the business in the 1960s, it was common to see two different versions of school history textbooks—one for in the Deep South and one for everywhere else, “and the difference was how you treated the Civil War.” By the mid-twentieth century, even textbooks that did not repeat the UDC party line still tiptoed carefully through the minefield. Take this passage, for example, from a widely used 1943 high school history textbook, which depicts a slave-holding South of stately mansions and benevolent slave owners: “The confederates . . . believed they were fighting for the democratic principle of freedom to manage their own affairs, just as the thirteen colonies had fought in the Revolutionary War.” The same textbook describes the Ku Klux Klan as a group that “sometimes” resorted to violence in its effort to retake local governments from the hands of incompetent former slaves. A 1965 textbook used in Alabama public schools taught another key point of the lost cause creed—that slavery was a benign institution: “In one respect, the slave was almost always better off than free laborers, white or black, of the same period [because] the slave received the best medical care which the times could offer.”

Publishers don’t offer a special “Southern” version of history anymore; these days, they cater to individual state educational standards, though some states—like California and Texas—have a disproportionate national influence on what those standards are. The problem today, the former publishing executive told me, is that “with so many state standards, the books have become in the last ten years longer, blander, more visual, certainly—and more inclusive. There’s so much to cover.” The result is like light beer: better tasting, less filling. With no space to truth-squad a 150-year-old public relations campaign, today’s texts simply strive not to offend; they don’t perpetrate the lost cause myth, but they don’t do much to correct it, either. Take this passage from a text widely used in public high schools today, which neatly splits the difference between the “states’ rights” and the “slavery” camps: “For the South, the primary aim of the war was to win recognition as an independent nation. Independence would allow Southerners to preserve their traditional way of life—a way of life that included slavery.” That’s a way of putting it even Miss Milly might have been able to live with.

“I grew up in a cocoon,” Herbers says today, recalling his childhood and the version of history he absorbed. It’s an apt metaphor for what happened to any Southerner born before about 1970, and to a good many of those born since. Although the field of Southern history underwent a revolution at the university level in the 1940s and 1950s, the version ordinary Southerners knew in 1970 and even later had not changed appreciably since 1900. Perhaps 1970 sounds like a long time ago, but in educational terms it’s not: 1970 was when a lot of people who are still teaching today learned what they know, and what they’ve passed on to their students. James Loewen, a sociologist and author of “Lies My Teacher Told Me,” has said that when he speaks to public school educators across the country today, somewhere between 60 and 75 percent say that the Civil War was fought over the issue of states’ rights. Whether the group he’s speaking to is predominately white, predominately black, or racially diverse, the percentage stays roughly the same.

The Southern version of history also prevailed for decades at Civil War battle sites, thanks to the fact that Congress appropriated money for the National Park Service, and Southerners in Congress had their hands on the purse strings. It wasn’t until the 1990s that the Park Service—under pressure from the academic community and a few members of Congress—made it a priority to revamp its exhibits to “interpret [the Civil War] and the causes of the war based on current scholarship,” said Dwight Pitcaithley, a professor of history at New Mexico State University who was chief historian of the Park Service from 1995 to 2005. In December 2008, Pitcaithley gave a talk to public school educators in Mississippi, and used as part of his presentation this quote from the Mississippi Declaration of Secession: “Our cause is thoroughly identified with the institution of slavery, the greatest material interest of the world.” That sentence is now prominently displayed on the wall of the National Park Service visitors’ center in Corinth, Mississippi, near the site of the battle of Shiloh. Pitcaithley took a picture of the display and used it in his presentation. After his talk, he was chatting with a thirty-four-year-old black school principal who had grown up in Mississippi, attended its public schools, and received his university education there. “I asked him if he’d ever seen that [quote] and he said no—he’d never even heard of that.”

All of which explains both how that dubious assertion that thousands of slaves fought in defense of the Confederacy came to be included in that Virginia textbook back in 2010, and how the error came to light. As it turns out, the textbook’s author took her information from the Sons of Confederate Veterans’ website; the error was discovered when a history professor at the College of William and Mary happened to come across it while browsing through a copy of one of her fourth grade daughter’s schoolbooks. Had that not happened, who knows how long the book would have been in use? To this day, it’s possible to stir up a hornet’s nest among ordinary Southerners by asserting that slavery was a primary cause of the Civil War; at the least, it will earn a native Southerner the accusation of having signed over his brain to those Ivy League intellectual snobs who despise all things Southern. The conviction that the South went to war primarily to defend the concept of states’ rights “is in [Southerners’] families, in their churches, in their schools, in their political structure,” Pitcaithley said. “They’ve been taught that over generations. It so embedded that—as you have found—if you suggest otherwise they look at you like you’ve put your pants on your head.”