Richard Pryor, who died in 2005, may be the greatest comedian the United States has ever produced. He transformed the medium, making it intensely personal and political, turning his caustic wit on racism, injustice, and himself.

Scott Saul’s book, Becoming Richard Pryor, is a deeply researched account of the author and comedian’s formation, both personally and socially. Saul, a historian and professor of English at the University of California Berkeley, interviewed more than eighty of Pryor’s family members and friends and dug up hundreds of documents that together help paint a picture of the world Pryor came out of and the world he helped shape.

In an interview several years ago on the California-based progressive radio show Against the Grain, radical journalist Sasha Lilley spoke with Saul about Pryor’s formative years in the segregated Midwest and the efflorescence of his art during a time of left-wing politics. Their conversation has been edited for length and clarity.