“However dreadful, it may be of use,” she said.

Jeffrey C. Stewart’s ‘The New Negro’

In “The New Negro: The Life of Alain Locke,” Stewart drew on vast research into Locke and his contemporaries, Jazz Age luminaries and prominent African-American artists, dancers, dramatists and novelists.

In his acceptance speech, Stewart recognized Locke’s struggles as a closeted gay man, noting that he created a community of artists as his family.

“If he was here right now accepting this award, he wouldn’t have family with him, as a gay man who lived a closeted life,” he said.

In recent years, the nonfiction category, like everything else in culture these days, has taken on pointed political overtones, populated with books about racism, mass incarceration and the rise of the religious and political right. This year’s finalists were a bit more thematically diverse. In addition to Stewart’s biography of Alain Locke, there was also a biography of the botanist David Hosack (Victoria Johnson’s “American Eden: David Hosack, Botany, and Medicine in the Garden of the Early Republic”) and Adam Winkler’s “We the Corporations: How American Businesses Won Their Civil Rights,” a history of how corporations gained power and influence in the United States, shaping national policies to grant companies rights that are comparable to those of individuals.

Some of the nominated books speak to our current politics and the growing cultural, political and class divide between rural and urban America, most notably Sarah Smarsh’s “Heartland: A Memoir of Working Hard and Being Broke in the Richest Country on Earth,” which chronicles her childhood in Kansas, where she grew up in a white working-class family, and addresses how poverty can trap people across generations.

Justin Phillip Reed’s ‘Indecency’