At the start of his "Civil War and Reconstruction" classes, U.S. Naval Academy Professor Craig Symonds learns about his students by asking this question: "What did your high school history teacher call the conflict?"

Students who say "the Civil War" are from the North, probably New England, he concludes. Those who respond "the War Between the States" can come from several areas of the country. But "the War of Southern Independence" invariably comes from Southerners, as does the rare -- though not extinct -- "War of Northern Aggression."

The answers also reveal that almost 150 years after the first shots echoed at Fort Sumter, and as students in history survey classes begin their springtime Civil War lessons, there is no common blueprint for teaching the most divisive of U.S. conflicts.

Although professional historians agree that the central cause of the war was the South's efforts to retain slavery, some amateur historians still fight about it. As a result, the way that students learn about the subject -- probably more than any other -- depends as much on their teacher's sensibilities as on state standards and textbooks.

In Loudoun County, for example, Rich Gillespie, an award-winning history teacher at Loudoun Valley High School, teaches that slavery was the chief cause but also emphasizes the psychological and other factors that drove both sides. Also in Loudoun, Ron Richards, an award-winning government teacher at Broad Run High School, tells students that political power was the cause of the war, not slavery.

"The issues are still alive and well today," said historian James M. McPherson, a Princeton University professor and author of "Battle Cry of Freedom: The Civil War Era." "Race relations, federal-state relations -- the raw emotions are there."

The place where emotions remain the rawest are in the South, where the war is more present in the minds of white people than it is for any other group in U.S. society, McPherson said. That is where, in the late 1800s, Confederate supporters promoted the teaching of the "Lost Cause," a view that slavery did not cause the war and that the Virginia theater was the most important.

The Lost Causers had remarkable success, and not just in the South, said John Marszalek, professor of history at Mississippi State University and author of 10 Civil War books. It wasn't until the 1960s, when the civil rights movement prompted new interest in the Civil War, that historical interpretation changed.

Slavery did cause the war, historians agreed, and they branded as distorted the standard view of Reconstruction. That highlighted Northern carpetbaggers and the claim that freed slaves were not ready to assume the responsibilities of citizenship, said Gary Nash, co-director of the National History Standards Project. Reconstruction should be taught, he said, as a failed attempt to create an intergrated society.

In some places, that thinking has been hard to accept.

Shannon Mallard, 28, a graduate student who teaches history at Mississippi State University, learned as a youngster in Atlanta the Lost Cause version: that Virginian Robert E. Lee was godlike, Union Gen. William Sherman was "the devil," and states' rights caused the war. A professor in Florida set him straight.

"But when I came to Mississippi State, I can honestly say that it is a sore point" among students from Mississippi high schools, he said. "Mentioning the fact that slavery was a direct cause is a big deal."

James Tuten, assistant provost and assistant professor of history at Juniata College in Pennsylvania, is a native of South Carolina. He has a state flag in his office and tries to be provocative in class by calling Sherman "the devil" and the conflict "the War of Northern Aggression."

"The problem here is that for white Southerners, slavery can't be the cause, because that ennobles the Union in the conflict and makes the South the 'bad guys' in the usual dialectic of good versus bad in all conflicts," he said. "No white Southerner wants to believe that great-great-great-granddaddy fought to defend slavery. Many historians, and I among them, make the distinction between what caused the war to happen and why people enlisted and fought. . . .

"The chief cause was slavery. This is only barely debatable. . . . However, most Southerners did not own slaves and believed they were fighting for defense of their homeland."

He influences his Northern-bred students, including Ruth Blaine, a freshman from Pennsylvania. "I always had a Northern view of the war," she said. "The South was the enemy. In Professor Tuten's class, I kind of get a better perspective of the South's pride. Before, I thought Southern pride was a bad thing, and they hated Yankees. Now I feel more sympathetic."

Ed Jackson, senior public service associate at the Carl Vinson Institute of Government at the University of Georgia, says the rise of state content standards and the publication of new textbooks have eliminated radical differences in teaching the war.

Yet some states don't have specific social studies standards, and some leave room for interpretation. In Northwest Washington, for example, Alice Deal Junior High School history teacher Cynthia Mostoller said she creates her own curriculum because there is none and because D.C. standards don't make sense. Last week, her history classes were trying to meet a math standard by using Maryland demographic data from the war era to plot graphs.

In Maryland, which is south of the Mason-Dixon line but did not secede, the attitude in schools is decidedly toward the Union.

"We pretty much have the Northern approach," said Mark Stout, social studies supervisor for Howard County schools. "But Virginia, once you are south of the Potomac. . . . People talk about the Mason-Dixon line, but [the division] is really the Potomac River."

Sensitivities about the war remain strong in Virginia, something Gillespie discovered after being raised in Massachusetts, where he considered himself an abolitionist. Moving to Loudoun County nearly 30 years ago, he discovered a distinct "Loudoun view" by talking to descendants of wartime families.

"You certainly get a chance to see what it felt like to be a Virginian and invaded by the federal government," he said. "To a degree, it was seen as an honorable thing to stand up against that. Virginians feel like they were victims."

Now he makes certain that his students understand the mind-set of each side and tries to make history come alive, he said.

One way he does that is by asking students to find out about their Civil War past. He recalled that in the mid-1970s, one student stood up and said, " 'My ancestor was born on the same plantation as Booker T. Washington, down in Franklin County, Virginia.' He was all aglow. About seven or eight kids later, a white kid says: 'This is a little embarrassing; my ancestor owned Booker T. Washington.'

"Now Northern Virginia has become such a mix of people that you have kids who say their ancestors were in Russia or Sweden," Gillespie said. "But even today, as you tie into kids' Civil War connections, it awakens a fascination in them, because it is one of the most tangible pieces of the past."

Eighth-graders Jared Tolbert, left, Logan Stommel and Racho Moutov discuss the Civil War at Alice Deal Junior High School in the District.