Jon Wiener teaches US history at UC Irvine.

The first page of Gore Vidal’s FBI file, released by the bureau after his death a year ago on July 31, is not about his political activism, his critique of the National Security State or even about his homosexuality. The first page, from 1960, says he made disparaging remarks about FBI Director J. Edgar Hoover.

The problem: Vidal’s play The Best Man (a satire of Washington politics with characters loosely based on real political figures) had just opened on Broadway, and the assistant special agent in charge of the New York City office sent a memo to Cartha DeLoach, Hoover’s right-hand man, informing him that the play contained “an unnecessary, quite unfunny and certainly unfair jibe [sic] at J. Edgar Hoover”—according to a show-biz columnist for a daily newspaper.

The bureau snapped to, informing DeLoach that “a Special Agent will attend this performance tonight” and that his report would be transmitted promptly. Indeed it was the supervisor of the New York FBI Office who was sent out on this mission. After seeing the play and taking notes, he filed his report: “The only reference to the Director [always capitalized] is when one play character—presumably Vice President Nixon—says to another—presumably Harry Truman, ‘J. Edgar Hoover considers you to be one of the most moral and religious men ever to be in the White House.’ The man replies with a sarcastic inflection, ‘I’ll reserve my opinion of J. Edgar Hoover for a posthumous memoir.’”...