A textbook distributed to Virginia fourth-graders says that thousands of African Americans fought for the South during the Civil War -- a claim rejected by most historians but often made by groups seeking to play down slavery's role as a cause of the conflict.

The passage appears in "Our Virginia: Past and Present," which was distributed in the state's public elementary schools for the first time last month. The author, Joy Masoff, who is not a trained historian but has written several books, said she found the information about black Confederate soldiers primarily through Internet research, which turned up work by members of the Sons of Confederate Veterans.

Scholars are nearly unanimous in calling these accounts of black Confederate soldiers a misrepresentation of history. Virginia education officials, after being told by The Washington Post of the issues related to the textbook, said that the vetting of the book was flawed and that they will contact school districts across the state to caution them against teaching the passage.

"Just because a book is approved doesn't mean the Department of Education endorses every sentence," said spokesman Charles Pyle. He also called the book's assertion about black Confederate soldiers "outside mainstream Civil War scholarship."

Masoff defended her work. "As controversial as it is, I stand by what I write," she said. "I am a fairly respected writer."

The issues first came to light after College of William & Mary historian Carol Sheriff opened her daughter's copy of "Our Virginia" and saw the reference to black Confederate soldiers.

"It's disconcerting that the next generation is being taught history based on an unfounded claim instead of accepted scholarship," Sheriff said. "It concerns me not just as a professional historian but as a parent."

Virginia, which is preparing to mark the 150th anniversary of the beginning of the Civil War, has long struggled to appropriately commemorate its Confederate past. The debate was reinvigorated this spring, when Gov. Robert F. Mc­Don­nell (R) introduced "Confederate History Month" in Virginia without mentioning slavery's role in the Civil War. He later apologized.

The Sons of Confederate Veterans, a group of male descendants of Confederate soldiers based in Columbia, Tenn., has long maintained that substantial numbers of black soldiers fought for the South The group's historian-in-chief, Charles Kelly Barrow, has written the book "Black Confederates."

The Sons of Confederate Veterans also disputes the widely accepted conclusion that the struggle over slavery was the main cause of the Civil War. Instead, the group says, the war was fought "to preserve their homes and livelihood," according to John Sawyer, chief of staff of the Sons of Confederate Veterans' Army of Northern Virginia. He said the group was pleased that a state textbook accepted some of its views.

The state's curriculum requires textbook publishers and educators to explore the role African Americans played in the Confederacy, including their work on plantations and on the sidelines of battle. Those standards have evolved in recent years to make lessons on the Civil War more inclusive in a state that is growing increasingly diverse.

When Masoff began work on the textbook, she said she consulted a variety of sources -- history books, experts and the Internet. But when it came to one of the Civil War's most controversial themes -- the role of African Americans in the Confederacy -- she relied primarily on an Internet search.