John A. Williams, a writer whose exploration of black identity, notably in the 1967 novel “The Man Who Cried I Am,” established him as one of the bright lights in what he liked to call “the second Harlem Renaissance,” and who caused a furor with an unflattering biography of the Rev. Dr. Martin Luther King Jr., died on Friday in a veterans’ home in Paramus, N.J. He was 89.

The cause was complications of Alzheimer’s disease, his son Dennis said.

Mr. Williams, whom the critic James L. de Jongh called “arguably the finest Afro-American novelist of his generation,” excelled in describing the inner lives of characters struggling to make sense of their experiences, their personal relationships and their place in a hostile society. His manifest gifts, however, earned him at best a twilight kind of fame — a reputation for being chronically underrated.

“Night Song,” his second novel, published in 1961, caught the attention of critics with its compelling picture of the jazz world of Greenwich Village and the retrospective ruminations of its hero, a dying saxophonist. “He gets close enough to the good novel about jazz that has never yet been written to make one hope he may write a good novel about something,” the British magazine The Spectator said in its review.

That novel was “The Man Who Cried I Am,” a look at 30 years of American history through the eyes of a dying black American writer living in Europe who reflects on his life and on his troubled marriage to a Dutch woman. Eliot Fremont-Smith, in his review for The New York Times, called it “a compelling novel, gracefully written, angry but acute, committed but controlled, obviously timely, but deserving of attention for far more than that.”