英语访谈节目:第一夫人米歇尔·奥巴马的美国血统

JEFFREY BROWN: And next: A new book takes a look at the roots of the first lady's family tree.

Gwen Ifill has that story.

GWEN IFILL: Among the four million slaves living in the United States on the eve of the Civil War, there was a 10-year-old girl who, a century-and-a-half later, would turn out to be the third-great-grandmother of Michelle Obama.

Even Mrs. Obama didn't know this family history until New York Times reporter Rachel Swarns unearthed her legacy in 2009. The first lady's ancestry, both black and white, are a complicated heritage shared by many Americans.

"American Tapestry," the story of the black, white, and multiracial ancestors of Michelle Obama, takes us on that journey. Its author, Rachel Swarns, joins me now.

Rachel, thanks for joining us.

You started out after having written about the story for The New York Times to find out about the genealogy of Michelle Obama, and instead you found the story of American history.

RACHEL SWARNS, author of "American Tapestry": That's right.

It really is the sweep of the country's history through the lens of one family, this first lady's family.

GWEN IFILL: A family that turned out to be not necessarily—you traced it backwards from knowing, of course, who—where it ended, but tracing it backward was kind of the drama.

RACHEL SWARNS: Right.

Well, the first lady has always known that she had white ancestors, but she didn't know who or when or where. And so I wanted to take the reader back into time to try and solve that mystery.

GWEN IFILL: Who was Melvinia?

RACHEL SWARNS: Melvinia was a slave girl valued at $475 in 1852, and she was the first lady's great-great-great-grandmother.

And she ended up going from a farm in Spartanburg, S.C., to Georgia, where she fathered a child, a biracial child. And the question has been, who was the father of that child?

GWEN IFILL: And so you set out to figure that out. But how do you trace that sort of thing?

RACHEL SWARNS: It's very challenging.

I mean, just telling these stories are challenging, particularly for African-Americans, because Melvinia was unusual. She appeared in a will. But before the Civil War, people simply didn't appear. African-Americans didn't appear in the census, and their marriages and births weren't chronicled in newspapers. So it's not easy.

GWEN IFILL: I noticed throughout the book you often had to fall into kind of a "this may have happened" construction. That must have been kind of frustrating for a reporter.

RACHEL SWARNS: It is. And the reality is that there are some things we just won't know.

GWEN IFILL: Was the path that you took—the path that they took, that this family took, was it typical? Was it—how widespread was it?

RACHEL SWARNS: She—her family story is very, very typical.

It is the story of so many Americans. And they basically had front-row seats to major moments in our history, from slavery to the Civil War, Reconstruction, segregation, the migration. It is a very, very American story.

GWEN IFILL: You—there was a lot written about when this book originally came out about Michelle Obama's white ancestors, even when you first wrote the story for The New York Times.

RACHEL SWARNS: That's right.

GWEN IFILL: How unusual was that, really? We can look now at the African-American experience and see it's a rainbow, as much as anything else.

RACHEL SWARNS: It is a rainbow. And many of us have those stories, and many people are finding that out through DNA testing themselves.

You know, with genealogy tools available online, with a cheek swab, and off it goes in the mail, a lot of ordinary people are finding these stories out and making these kinds of connections.

GWEN IFILL: But it raises lots of uncomfortable questions, too, especially about how the original connection happened.