In the nonfiction category, Tim Weiner, a reporter at The New York Times, took the [National Book Award] prize for “Legacy of Ashes: The History of the C.I.A.” (Doubleday).

Mr. Weiner, who won a Pulitzer Prize for his reporting on national security programs, examined more than 50,000 documents and interviewed hundreds of C.I.A. veterans for his book, a critical history of C.I.A. failures.

Accepting the award, Mr. Weiner said his work was “a testament to the power of the record revealed and maybe to the fact that our democracy, in spite of everything, is still open enough to see a glimpse of what we have wrought abroad.”