When I first met Howard Zinn 40 years ago, I had known him as a leading antiwar critic, civil rights activist and radical historian. I expected a brooding and perhaps angry intellectual deeply at odds with a nation that shortly afterward reelected Richard Nixon by a landslide. But my first impression of him, sitting in his office at Boston University, was of a casual, jovial and self-deprecating professor who, I learned, was provoked to a kind of controlled fury only by war and injustice. It was an impression shared by his legions of friends.

Zinn was a force in the civil rights movement and one of the originators of oral history and history “from below.” His work in the South in the 1950s and early ’60s, while he taught at Spelman College in Atlanta, was galvanizing for a new generation of black students, Alice Walker, Julian Bond and Marian Wright Edelman among them. He helped guide the Student Nonviolent Coordinating Committee, a major component of the black uprising, and wrote a number of seminal articles and books about the movement, including “The Southern Mystique” and “SNCC: The New Abolitionists.”...

When he died in January 2010, the obituaries commonly focused on the Vietnam War and civil rights periods of his life. But as Martin Duberman smartly lays out in his new biography, there was a lot more to Zinn’s remarkable role in the glory days of the movement and the phenomenon that is “A People’s History.”...