Dolen Perkins-Valdez was reading a biography of W.E.B. DuBois when she came across the small aside. It was piece of history she hadn't known, and couldn't stop thinking about.

The land for Ohio's Wilberforce University, the nation's oldest private historically black college, where DuBois had once taught, at one time had been part of a resort - a place called Tawawa House, where wealthy Southern slaveholders would take their slave mistresses for open-air "vacations."

"I had never heard of anything like that," says Perkins-Valdez, then a writing professor at the University of Mary Washington. She knew of masters taking slaves north to attend to them, "but the thought of them taking women to a vacation resort was just stunning to me. I didn't know what to do with that."

What she did first was wonder: How would they have gotten there? And what did the resort look like? Then she asked: Why would a slave taken to a Northern free state not run?

Her attempts to answer those questions turned into the novel "Wench," out in paperback Tuesday, just in time for the 150th anniversary of the Civil War.

It's the story of four slave mistresses - "wenches "- who become furtive friends at Tawawa House. They contemplate freedom, learn each other's stories and deepest fears. Some stories are brutal, but the main character, Lizzie, sleeps in the same bed with her owner, the father of her two children, and thinks herself in love with him. And he with her.

"Wench," which went through seven printings after its hardcover release last January and has a first paperback printing of 135,000, raises questions about complex parts of slavery that are less explored for lack of written accounts: What kinds of accommodations and negotiations took place between slaves and masters? What passed for love? The novel looks at what history gets privileged and what gets forgotten.

Sitting in the library of the Northwest Washington home she shares with her husband and 3-year-old daughter, Perkins-Valdez, a Harvard grad with a PhD in American literature from George Washington University, talks about her main character and reaction to the book.

Lizzie, who sometimes intimately calls her master by his first name, lives in the master's house and eats better food than the other slaves. Her children are being educated and wear better clothes. And Lizzie constantly presses her owner to free their children - children his wife couldn't give him and whom she refuses to leave motherless at the Tennessee plantation so she can escape.

"In an early draft of the book, I had Lizzie completely in love with Drayle," Perkins-Valdez says. "I talked to another writer who said, 'I don't think love could exist in this situation that wasn't a negotiation.' Slaves didn't have the agency that would really allow them to barter, but there are a million and one everyday ways slaves manipulated and maneuvered" to try to better their way.

Both black and white readers have struggled with the plausibility of the relationships in the novel, the author says. White women have expressed doubt that Southern wives would have stayed married to men who fathered children with slaves. Black readers can't stomach a slave woman loving a master. Perkins-Valdez points out that slavery involved human beings who had dominion over other human beings, and the whole range of human emotion and action were possible.

Perkins-Valdez read original manuscripts and searched for documentation beyond the mention in the Lewis biography but found little. Wilberforce University has a plaque commemorating Tawawa House, but even the Ohio Historical Society didn't know that history.

"I had a hard time finding anything that gave me what I wanted, which was someone saying, 'I brought my slave here. She was my mistress,'â??" she says.

Pulitzer-winning DuBois biographer David Levering Lewis and Ohio historian Donald Hutslar both cited a few primary documents, buttressed by anecdotal evidence and oral histories.

But "I think there's sort of a tendency toward disbelief" with oral histories, often a slave's only record, Perkins-Valdez says. "Most slaves were illiterate and even when they were literate, their writings didn't survive."

Non-establishment sources are often disregarded, says George Washington University historian Adele Logan Alexander. "Oral history, or when you have a song or something like that, that is not as accepted in the canon, and it's harder to push the legitimacy of that source."

Alexander, author of the book "Ambiguous Lives: Free Women of Color in Rural Georgia, 1789-1879," says nuance in slavery gets painted over all the time. "People had to make their accommodations, and I think that Perkins-Valdez deals with those ambiguities of history quite well."

Perkins-Valdez says the book has prompted others to share their family oral histories with her. When she explained that the book was about black slave mistresses and their owners, a Smithsonian museum guard said: "Oh, like my great-grandmother."

A reader e-mailed to say she'd heard civil rights leader Julian Bond refer to the book in speech, calling it his family's oral history as well. Reached by phone, Bond said: "I often talk about that history. My great-grandmother was a slave. She had been given to a woman as a wedding present, and when the bride became pregnant, the bride's husband, my great-grandmother's owner and master, exercised his right to take his wife's slave as his mistress. He was a Presbyterian minister. Two children came from that union, James Bond and Henry Bond, and James Bond was my grandfather."

But the most intriguing story came from Margretta Browne of Silver Spring, a high school English teacher and friend of Perkins-Valdez.

Browne says she is one of five Margrettas with the first, according to family history, being the daughter of President Andrew Johnson and a slave named Tabitha Short. This claim has not been addressed by historians, though there is record of a mulatto house slave named Margret. But the family's oral history points out, as evidence, that Margretta was educated and given a set of dishes and silverware by the president (the family still has them); she became a teacher after Emancipation. The name skips two generations, then picks back up with Browne's grandmother, her mother, then Browne (one of six generations of teachers) and now her 5-year-old daughter.

Browne called "Wench" hard to read. "I didn't know whether to embrace all of this, or get angry and put it down. There was just so much in it that you don't always hear," she says. "That's what made me think about my family and the Margrettas." It's a history they've never shared outside the family.

"I think there's a blank spot, there's a void for a lot of African Americans in terms of history that is written down and isn't embraced by the nation as a whole and seen as something we can talk about openly. The blank spot is what Dolen wrote about and it's a lot more complex than here's the master, here's the servant."

Wench: A Novel

by Dolen Perkins-Valdez

Amistad. 304 pp.