Five million public school students in Texas will begin using new social studies textbooks this fall based on state academic standards that barely address racial segregation. The state’s guidelines for teaching American history also do not mention the Ku Klux Klan or Jim Crow laws.

And when it comes to the Civil War, children are supposed to learn that the conflict was caused by “sectionalism, states’ rights and slavery” — written deliberately in that order to telegraph slavery’s secondary role in driving the conflict, according to some members of the state board of education.

Slavery was a “side issue to the Civil War,” said Pat Hardy, a Republican board member, when the board adopted the standards in 2010. “There would be those who would say the reason for the Civil War was over slavery. No. It was over states’ rights.”

The killings of nine black parishioners in a South Carolina church last month sparked a broad backlash against the Confederate battle flag , to some a symbol of Southern heritage but to others a divisive sign of slavery and racism.

There is also a call to reexamine a quieter but just as contentious aspect of the Civil War in American society — how the history of the war, so central to our nation’s understanding of itself, is presented in public school classrooms and textbooks.

“It’s the obvious question, it seems to me. Not only are we worried about the flags and statues and all that, but what the hell are kids learning?” said Dan Quinn of the Texas Freedom Network, a left-leaning advocacy organization that has been critical of the state’s academic standards in social studies.

If teaching history is how society shows younger generations who they are and where they came from, the Civil War presents unique challenges, especially because of the fundamental differences in the way the cause of the war is perceived 150 years after its last battle.

Nowhere is the rejection of slavery’s central role more apparent than in Texas, where elected members of the state board of education revised state social studies standards in 2010 to correct for what they said was a liberal slant.

Students in Texas are required to read the speech Jefferson Davis gave when he was inaugurated president of the Confederate States of America, an address that does not mention slavery. But students are not required to read a famous speech by Alexander Stephens, Davis’s vice president, in which he explained that the South’s desire to preserve slavery was the cornerstone of its new government and “the immediate cause of the late rupture and present revolution.”

Rod Paige, a Republican who served as education secretary under President George W. Bush, was among those who criticized the Texas board for minimizing difficult parts of the nation’s past.

“I’m of the view that the history of slavery and civil rights are dominant elements of our history and have shaped who we are today,” Paige told the board at the time, according to the Texas Tribune . “We may not like our history, but it’s history.”

More than 500 activists cruised into Russellville, Ark., on Sunday to show support for the embattled Confederate flag, seen by many as a symbol of racism and slavery. (Reuters)

Historians acknowledge that disagreements over states’ rights played a role in the Civil War. But the states’ rights issue was inseparable from slavery, they say: The right that states in the South were seeking to protect, after all, was the right to buy and sell people.

Southern states made that clear in their declarations of independence from the union, said James Grossman, the executive director of the American Historical Association. Slavery’s primary role in driving the Civil War is a matter of scholarly consensus, he said.

“The War happened only because of the determination of the leadership of eleven states to defend the right of their residents to own other human beings,” Grossman wrote in an e-mail. “The Civil War was fought over the issue of slavery.”

Hardy, the Texas state board member who said the war was not about slavery, did not respond to requests for comment. The board’s chair, Donna Bahorich, also did not respond to a request for comment.

Quinn, of the Texas Freedom Network, said the new textbooks that will arrive in Texas classrooms this fall manage to “thread the needle,” meeting state standards while still acknowledging the importance of slavery.

“But the books muddy things by presenting sectionalism and states’ rights ideas throughout,” he said. “A lot of white southerners have grown up believing that the Confederacy’s struggle was somehow a noble cause rather than a war in the defense of a horrific institution that enslaved millions of human beings.”

Texas’s social studies standards are more politicized than any other state, said Jeremy A. Stern, a historian who reviewed state standards for the conservative-leaning Thomas B. Fordham Institute in 2011. He gave Texas’s standards a D and wrote that the board was “molding the telling of the past to justify its current views.”

Stern said the social studies standards in South Carolina — where the Civil War started, and where, in June, Dylann Roof allegedly gunned down nine black parishioners — deserve an “A” and honestly address slavery’s role in the conflict while also nodding to states’ rights as an important issue at the time.

“Are Southern states soft-pedaling the Civil War? By and large, the answer to that would be no,” Stern said. But he said there is often a difference between state standards and what children actually learn.

For decades, some Southerners have emphasized states’ rights as the cause of the war. Nearly half of Americans — 48 percent — believe that states’ rights was the main cause of the war, compared to 38 percent who said the main cause was slavery, according to a 2011 Pew Research Center survey.

Raul Cevallos, a 2015 graduate of Texas Tech University, said he was taught at his Dallas-area high school that the war was caused by slavery. But he said a group he founded to create political awareness last year found that many young people are ignorant about history.

The group asked students three simple questions about the United States, including “Who won the Civil War?” for a video that later went viral online. “The Confederates,” answered one student. “The South,” said another. Others said they’re weren’t sure. But the same students answered questions about pop culture — “Who is married to Brad Pitt?” — correctly.

“If you don’t know about the Civil War, and you don’t know about things like slavery, then you wouldn’t really be able to understand why our society is the way it is today,” Cevallos said.

James W. Loewen , a sociologist who wrote the best-selling book “Lies My Teacher Told Me ,” says textbooks perpetuate myths about the Civil War in order to avoid offending state textbook-adoption panels. Nineteen states, including almost all of those in the South, adopt textbooks at the state level, according to the Association of American Publishers.

“I think we are at last seeing the de-Confederatization of America,” Loewen said. “And I’m hoping that we will see some action towards de-Confederatizing our textbooks.”

Loewen, who has reviewed many textbooks, said he has found many errors and omissions that help de-emphasize the role slavery played in causing the war. Among the biggest and most common problems, he said, is textbooks’ failure to quote from key primary sources: the Southern states’ declarations of secession, which made clear that they were leaving the union to protect white citizens’ right to own slaves.

“Our position is clearly identified with the institution of slavery,” reads Mississippi’s declaration , signed in 1861.

Loewen identified one textbook — “American Pageant ,” in print for more than half a century — that quoted directly from South Carolina’s secession document. That’s admirable, Loewen said, but the quotation leaves out the document’s direct language about the role of slavery in driving South Carolina’s decision.

History can be a “weapon,” Loewen said, and it has been used “against all of us. It makes us all stupid about the past and thoughtless about the present.”

David M. Kennedy , a Stanford professor emeritus and Pulitzer Prize-winning historian who co-authored “American Pageant,” said Loewen is nitpicking.

“I would defy anybody who read our text to conclude that we were unaware of slavery as the cause of the Civil War,” Kennedy said. He added that he and his co-author have bade farewell in the past to states that found the textbook’s content objectionable. Alabama has rejected the book for years because of what state officials consider derogatory portrayals of 19th century religious revivals, among other reasons.

“We’re not in the business of compromising our view of history so some state school board will be happy,” Kennedy said.

Publishers of other textbooks also pushed back against Loewen’s criticisms.

“Current titles for middle and high school students clearly state that the Southern states’ desire to preserve slavery was the primary reason for secession,” said Laura Gamble, a spokeswoman for Pearson.

Critics of Texas’s new history standards fear that their teaching about the Civil War will spread to other states via textbooks that cater to the Lone Star state; Texas is the second-largest market in the country.

But that narrative appears to be changing as digital books help publishers become more nimble, said Jay Diskey of the Association of American Publishers.

A spokesman for the publisher McGraw-Hill Education, asked whether the company changes Civil War-related passages in books used outside Texas, said the company provides “content that is tailored to the educational standards of states.”

Stephen Wright, an eighth-grade teacher in Nacogdoches, a small and conservative East Texas town, said some Texas students undoubtedly leave their classrooms believing that slavery was not the primary cause of the Civil War. But not his students.

Wright said he has his students read the Southern state declarations of secession to learn for themselves what the war was about. He deals with the Civil War standards — he has to teach the standards, because they might show up on the state’s history test — by explaining the reasons that “some people believe” the war happened.

“Man, it’s all about slavery,” he said. “The students know that.”