Instrumental in the work behind the best-selling Autobiography of Mark Twain, Volume 1, Hirst has been curator of the Mark Twain Papers and general editor of the Mark Twain Project at The Bancroft Library since 1980. After earning a B.A. in English at Harvard, he came to the English department at Berkeley for his real education. As a graduate student at Cal, Hirst took a job as a fact-checker and proofreader at the Mark Twain Papers in 1967, when the university was just beginning the scholarly edition of which he is now head. He became an adjunct professor in 1996 and has since taught one course a year for the English department at Berkeley.