Reisha Raney’s role in Friday night’s Daughters of the American Revolution ceremony for the military was minor. She carried Virginia’s flag in a procession that walked a few steps down a carpeted aisle at Constitution Hall and then stood perfectly still.

But for Raney, an African American raised in Prince George’s County, it was one of the most pivotal moments in her life. Her place in the DAR, a predominantly white organization whose annual convention at Constitution Hall in the District ends Sunday, was proof of her extraordinary family history.

The group certified research that traced Raney’s roots to William Turpin, a patriot who fought against the British in the Revolutionary War. Turpin’s mother was Mary Jefferson, the aunt of the nation’s third president, Thomas Jefferson.

Raney respects her ties to Jefferson, but he’s not the reason the 39-year-old Fort Washington resident went to a beauty salon, slipped on a flowing white gown and smiled like a beauty-pageant contestant as she walked the halls of a group that at one time barred black people.

She was honoring William Turpin’s son, Edwin, Jefferson’s second cousin, who purchased a slave, Mary, and married her in Canada. The two lived in neighboring houses on a plantation in Goochland County, Va. The houses were burned when word got out, and then were rebuilt, according to a family memoir. Before his death in 1868, Edwin wrote in a will that the children he had with “my woman Mary” were to be free.

Reisha Raney is a descendant of Thomas Jefferson’s family. She is photographed in the Connecticut Board Room inside DAR Constitution Hall in Washington, D.C. on June 28, 2013. (Marvin Joseph/The Washington Post)

“What I’m going to think about as I walk down that aisle is Edwin and Mary rebuilding that house,” Raney said as she prepared for the DAR ceremony honoring national defense, where an Army band played “This Is My Country.” “I’ll think about those torches. I’m doing this for my family.”

Raney, a systems engineer and mathematician with degrees from Spelman College and the Georgia Institute of Technology in Atlanta, talks less about Jefferson than about the couple who intertwined her black family’s line with that of the Turpins. She’s the leader of the Fort Washington chapter of the DAR, Harmony Hall, and is credited with saving it from being dissolved by recruiting younger women as older members passed away.

“I have no doubt in my mind she will move on to become a state officer or national officer” in the DAR, said Dorothy Weberling, 64, a former leader of Harmony Hall who processed Raney’s application. “She’s just that smart.”

There’s no doubting that Raney belongs, said Weberling, who’s white. “The ladies who’ve accepted her are all college women. They have a greater understanding of history and what actually happened. What we’re bringing out into the open is that white men and black women did have relationships. It’s better to bring the secrets out.”

It’s rare that black family history such as Raney’s is unearthed, traced and documented, historians said. It’s rarer still when it’s linked to a storied family with power, privilege and a celebrated legacy. Jefferson’s intimate relationship with his young slave, Sally Hemings, is one of a few.

Tens of thousands of fair-complexioned black people like Raney can only guess at their origins because of the secrets that hid them, historians said — and because of records that were lost, burned or never searched.

It makes entry into groups such as the DAR harder for African American women, said Darryn Lickliter, the group’s director of genealogy. The DAR, established in 1890 to recognize descendants of patriots who fought for American independence, uses rigorous genealogy searches to verify the claims of applicants.

Ancestors Edwin Durock Turpin, his wife Anna Elizabeth CochranTurpin and their two children Martha Jane, left, and Edwin Durock Jr. circa 1874. (The book: All Is Never Said)

Many years ago, the group took the added step of barring black women from its ranks. The DAR is still working to repair its reputation, which was marred decades ago after it blocked Marian Anderson, one of the world’s most famous opera singers, from performing at a 1939 concert at Constitution Hall because she was black.

Its highest-profile member, then-first lady Eleanor Roosevelt, quit in protest. In the years since, the DAR apologized profusely and invited Anderson to perform at Constitution Hall several times before her death in 1993. It also opened the hall to numerous black entertainers, whose posters currently adorn its walls.

Wilhelmena Rhodes Kelly, 66, a genealogist and writer who joined the DAR nine years ago and became the first black woman to start a chapter last year, in Queens, said the group has changed. “Not everybody is going to hug you, but I’ve never felt discrimination in any way, I can honestly say that.”

The DAR is trying to strengthen its ties to nonwhite women in other ways. In the 1980s, it started Forgotten Patriots, a project that works to identify black and Native American men who fought in the Revolutionary War, so that descendants can more easily link to them.

The project sometimes shines a light on long-hidden relationships between slaveholders and slaves. The “DAR is trying to make its records accurate to show the true history of the situation,” said Eric Grundset, its library director.

New England states have the best 18th-century records because “they used a lot of color descriptions,” he said. “But the further south you go, the worse it gets.”

Raney heard family members in Maryland talk about links to Thomas Jefferson’s relatives but paid it little mind.

A distant cousin in Louisiana, Odette Harper Hines, 100, provided an oral history, “All Is Never Said,” that detailed Edwin and Mary Turpin’s story as passed down by elderly family members, but Raney still didn’t quite believe.

In 2006, that changed. She watched “African American Lives,” a show in which Harvard professor Henry Louis Gates Jr. traced the histories of famous people. As soon as it ended, she called genealogy company African Ancestry to submit a DNA test, hoping to find her origin “somewhere in Africa.”

A sequence of DNA tests placed her ancestors in Mali and other west African countries, but also contained a surprise — she was 30 percent European.

Digging deeper, she spent thousands of dollars ordering more DNA tests for herself, her mother, Carolyn, and her father, Robert.

Her father’s result, which came in the middle of the DAR’s months-long process of certifying her family tree, “blew my mind,” Raney said. He was 64 percent European.

“My dad,” she said, “was a white man.”

“It blew my mind, too,” Robert Raney said in a telephone interview from his home in Suffolk, Va. He strongly identifies as black because of culture and the way he looks. “I was the darkest person in my family. At one time, I thought I was adopted,” he said.

Family documents played a role in the DAR’s certification, too. Augustus Granger, Raney’s third cousin, has researched the family’s history for 20 years.

Edwin Turpin bought a farm in Goochland County once owned by his famous second cousin, Thomas Jefferson. In the will in which Turpin declared his children free, he also left them all his possessions.

Edwin’s and Mary’s names turned up on documents from four years after his death, in 1868, when a son, Thomas H. Turpin, signed papers at the Freedmen’s Bureau, a federal agency that helped freed slaves.

Thomas Turpin’s occupation was recorded as a painter and his complexion as light. The names of his mother and father, and those of eight brothers and sisters, living and dead, were also listed.

Raney said she identifies as African American, but it’s a complicated history. A brave and loving white man is in the picture, as are his children, who could pass for white but have struck up relationships with women who look more like their dark-skinned mom.

“I just feel like I always constantly have to explain myself to people who don’t understand why I joined DAR,” Raney said. She fingered pins on her chest that the DAR awarded for her service and the contributions of her ancestors.

“I earned these,” Raney said.

Twitter: @bydarrylfears