I have never been an enthusiast for the work of the leftist historian Howard Zinn, though I grant that he has been influential.  In October the New Press will bring out a biography by a fellow leftist, Martin Duberman.  The Kirkus review is not kind:

“A star-struck biography of the prominent historian and activist.”

“Howard Zinn (1992–2010) is best known as the author of the controversial A People’s History of the United States (1979), written to counteract a perceived bias toward the wealthy and privileged in standard history textbooks by highlighting the contributions of those conventionally omitted. Though as unbalanced in one direction as Zinn felt the standard texts were in another, it has been widely influential in affecting the content of a whole generation of textbooks and course syllabi. Zinn presents a challenge for a biographer. During the 1960s, he worked courageously in the civil rights movement and against the Vietnam War; he was closely associated with such prominent figures as Stokely Carmichael, Tom Hayden and Daniel Ellsberg. His emotional life, however, is inaccessible; Zinn disliked discussing emotions and ruthlessly purged his archives of anything touching on feelings or relationships. Apart from an increasing attraction to anarchism, Zinn’s political philosophy never evolved much beyond the conventional socialism he adopted in adolescence. Nor did he move on from the issues of the ’60s to newer causes like women’s and gay rights or globalization. Throughout a long academic career, he confined himself to discussing racial and labor issues and opposing various American military interventions. Consequently, little remains to a biographer but a succession of demonstrations attended, books and articles written, and feuds with two college presidents. By way of context, prize-winning author Duberman (History Emeritus/CUNY Graduate School; A Saving Remnant: The Radical Lives of Barbara Deming and David McReynolds, 2011, etc.) includes summaries of contemporaneous American history presented from a tendentious leftist viewpoint. While Duberman may criticize some of Zinn’s writing as simplistic, one-sided or impractical, he clearly has no interest in challenging its fundamental political underpinnings.

“Recommended for readers already smitten with Zinn.”

Another historian, Michael Kazin, effectively assessed Zinn's failings in 2004: http://www.dissentmagazine.org/article/?article=385