Jesmyn Ward won the National Book Award for fiction on Wednesday night for “Sing, Unburied, Sing,” a dark, fablelike family epic set in contemporary Mississippi that grapples with race, poverty and the psychic scars of past violence.

The novel, which critics compared to works by William Faulkner and Toni Morrison, features a 13-year-old boy named Jojo, whose drug-addicted mother takes him and his toddler sister on a road trip to pick up their white father when he is released from prison. The judges called the book “a narrative so beautifully taut and heartbreakingly eloquent that it stops the breath.”

Ms. Ward, a Mississippi native who received a grant from the MacArthur Foundation this year, is now a two-time National Book Award winner: She previously won the fiction award in 2011 for her novel “Salvage the Bones.”

In her acceptance speech, she noted that occasionally in her career, she has faced skepticism from people who doubted that there was a commercial audience for fiction about poor black Southerners.