THIS FALL, Texas schools will teach students that Moses played a bigger role in inspiring the Constitution than slavery did in starting the Civil War. The Lone Star State’s new social studies textbooks, deliberately written to play down slavery’s role in Southern history, do not threaten only Texans — they pose a danger to schoolchildren all over the country.

The Texas board of education adopted a revised social studies curriculum in 2010 after a fierce battle. When it came to social studies standards, conservatives championing causes from a focus on the biblical underpinnings of our legal system to a whitewashed picture of race in the United States won out. The guidelines for teaching Civil War history were particularly concerning: They teach that “sectionalism, states’ rights and slavery” — carefully ordered to stress the first two and shrug off the last — caused the conflict. Come August, the first textbooks catering to the changed curriculum will make their way to Texas classrooms.

It is alarming that 150 years after the Civil War’s end children are learning that slavery was, as one Texas board of education member put it in 2010, “a side issue.” No serious scholar agrees. Every additional issue at play in 1861 was secondary to slavery — not the other way around. By distorting history, Texas tells its students a dishonest and damaging story about the United States that prevents children from understanding the country today. Also troubling, Texas’s standards look likely to affect more than just Texans: The state is the second-largest in the nation, which means books designed for its students may find their way into schools elsewhere, too.

School districts and publishing companies could work around the misguided guidelines, but it would take some gumption. Though a 2011 law allows Texas schools to teach from textbooks that the board has not pre-approved, buying from the state’s shopping list is simpler. And big publishing companies are unlikely to deviate from the standards dictated by such a huge market. It would be nice if publishers sacrificed a bit of profit to preserve academic integrity and if schools purchased only books that meet higher standards of honesty. But the true onus to do better lies with the Texas policymakers who decide what students should be taught.

Texas is in good company when it comes to weak history standards. Many other state guidelines are vague or confusing, and allow for uneven teaching. Yet Texas is rare for the brazenly political way board members devised its curriculum.