Author and filmmaker James McBride has the won the National Book Award for fiction for his novel “The Good Lord Bird.”

NEW YORK — James McBride’s “The Good Lord Bird,” the comic and terrifying adventures of a disguised black child caught up in John Brown’s abolitionist crusade, was the winner Wednesday night of the National Book Award for fiction.

George Packer’s brutal examination of the modern class wars, “The Unwinding: An Inner History of the New America,” won for nonfiction during a dinner ceremony at Cipriani Wall Street in downtown Manhattan. Cynthia Kadohata’s “The Thing About Luck” won for young people’s literature and Mary Szybist’s “Incardine” won for poetry.

McBride, the picture of style in a tux and pork pie hat, confided during his acceptance speech that in recent years his mother and niece had died and that his marriage had collapsed. He found consolation in his novel and its protagonist, a boy pretending to be a girl and nicknamed “Onion” by Brown, who recruited him for his ill-fated attempt to free the slaves.

“It was always nice to have somebody whose world I could just fall into and just follow him around,” said McBride, best known for his million-selling memoir “The Color of Water.”

Packer, a staff writer for The New Yorker, praised some of the workers who allowed him to tell their stories.

He said that he hoped his book would “illuminate some of what’s gone wrong in America” in recent years” but also “some of what’s gone right.”