Asked to name the most famous Americans in history, high school students put 20th-century black Americans in the top three slots. Topping the list: the Rev. Martin Luther King Jr., Rosa Parks and Harriet Tubman. Three of the top five — and six of the top 10 — are women.

Sam Wineburg, the Stanford University education and history professor who led the study along with Chauncey Monte-Sano of the University of Maryland, says the prominence of black Americans signals "a profound change" in how we see history.

"Over the course of about 44 years, we've had a revolution in the people who we come to think about to represent the American story," Wineburg says. "There's a kind of shift going on, from the narrative of the founders, which is the national mythic narrative, to the narrative of expanding rights."

Yes, but how does he explain No. 7: Oprah Winfrey? She has "a kind of symbolic status similar to Benjamin Franklin," Wineburg says. "These are people who have a kind of popularity and recognition because they're distinguished in so many venues."

Researchers told a diverse group of 2,000 juniors and seniors in all 50 states: "Starting from Columbus to the present day, jot down the names of the most famous Americans in history."

For what it's worth, when the researchers polled 2,000 adults in a different survey, their lists were nearly identical. To Wineburg, that shows that what's studied in school affects not just children but the adults who help them with their schoolwork.

The study acknowledges that the emphasis on African-American figures by the schools leaves behind not only 18th- and 19th-century figures but others as well, such as Hispanic icon Cesar Chavez, Native American heroes such as Pocahontas and Sacagawea and labor leaders such as Samuel Gompers and Eugene V. Debs.

At the same time, the study, scheduled to appear in the March issue of "The Journal of American History," notes that teachers the researchers talked to while giving the quiz predicted that student lists would be top-heavy with entertainers and celebrities. Aside from Winfrey and Marilyn Monroe, entertainers appear "nowhere near the top" of the lists.