Leak: Why Mark Felt Became Deep Throat

Through the shadowy persona of “Deep Throat,” FBI official Mark Felt became as famous as the Watergate scandal his “leaks” helped uncover. Best known through Hal Holbrook’s portrayal in the film version of Bob Woodward and Carl Bernstein’s All the President’s Men, Felt was regarded for decades as a conscientious but highly secretive whistleblower who shunned the limelight. Yet even after he finally revealed his identity in 2005, questions about his true motivations persisted.

Max Holland has...