It would be easy to assume that a desire to document an enslaved woman’s rightful place in history started Annette Gordon-Reed down the path that led to her recent triumph as the winner of the National Book Award for nonfiction.

But it is a fascination with Thomas Jefferson himself, not Sally Hemings or the bonds between them, that has captivated this scholar and writer since her childhood.

Long before she knew about Hemings or her children and what their relationship to Jefferson might be, Gordon-Reed recalls that a biography she read in grade school sparked her interest in America’s third president and founding father. She developed a deep curiosity about the man who owned slaves yet helped to carve a new Democratic nation out of the fractious colonies. Gordon-Reed continued her studies of Jefferson while majoring in history at Dartmouth College.

“I first became interested in Jefferson and what interested me was that he liked books, and I like books,” she recalls. “He was interested in architecture and I was interested in architecture, but what interested me most was he was involved in writing the Declaration of Independence … Here was a person who was involved in the beginning of a country, creating a nation. It is really about the founding of a country.”

Dr. Gordon-Reed, who is a history professor at Rutgers University in Newark, N.J., as well as a professor of law at New York Law School, became the first African-American woman to win the National Book Awards nonfiction prize at a ceremony in New York last month for her book, The Hemingses of Monticello. She is also the first Black author to win the nonfiction prize since 1991 when Orlando Patterson won for Freedom. Other African-Americans have won in other categories.

Her book examines the lives of Sally, her siblings and her children born and reared at Monticello and owned by Jefferson.

Hemings, as Gordon-Reed writes, was also Jefferson’s wife’s half-sister.