This article reports on the identity of the man known as Deep Throat. "I'm the guy they used to call Deep Throat," Mark Felt said, as quoted in Vanity Fair, and aging antagonists rushed to their battle stations. This was, undeniably, a major moment in the annals of U.S. politics and journalism. After three decades of obsessive speculation, we finally know the identity of the shadowy, chain-smoking figure (Hal Holbrook in the movie) who talked to the Washington Post's Bob Woodward in a dark parking garage, in meetings arranged after the reporter moved an empty flowerpot on his balcony or Deep Throat had clock hands drawn on Woodward's morning paper. Felt is 91 now, slightly stooped, and suffering the after-effects of a stroke. His relatives spoke for him when the inevitable press horde descended on his California doorstep.With Felt's incalculable assistance, the stories by Woodward and Carl Bernstein led to congressional investigations, an impeachment inquiry and, ultimately, to the resignation of the incorrigibly corrupt Richard Nixon. Mark Felt was no saint. Nixon had passed him over for the FBI's top job, so his motivation could have been partly personal. In 1980, he was convicted of approving break-ins at the homes of people associated with the radical Weather Underground We all live in a post-Watergate world. People distrust their governments; they distrust the media. They've been given ample cause by both institutions. But before we rush out to revise history—before we blame whistle-blowers or ban journalists' use of anonymous sources—let's recall the most celebrated whistle-blower and anonymous source of all.