Despite many serious scholars’ denunciations, Howard Zinn’s A People’s History of the United States has enjoyed phenomenal success since its publication in 1980: 2.6 million (!) copies sold, incorporation into the curricula of innumerable schools, and the achievement of almost iconic status in popular culture. Mary Grabar’s Debunking Howard Zinn: Exposing the Fake History That Turned a Generation against America performs a valuable service by examining Zinn’s polemical volume and revealing “just how distorted, manipulative, and plain dishonest” it truly is. A tireless left-wing activist with a Ph.D. in history, Zinn (1922–2010) urged fellow historians, as Grabar relates, to eschew...