This evening, at a Barnes and Noble store at Tysons mall in Fairfax County, VA, I found a book by Douglas M. Charles, "Hoover’s War on Gays: Exposing the FBI’s ‘Sex Deviates’ Program", published by the University of Kansas Press in 2015.
The hardcover, at over 450 pages, is rather pricey ($30) and it will take some time before I can read it and review it on the Books blog. But the prologue of the book explains that gay history probably has not accounted for the way the FBI was influenced by an intense animus towards homosexuals that did not start to loosen until the late 1960s, and then gradually. The first chapter, “Was J. Edgar Hoover gay? Does it matter?” explains that there was not much attention to homosexuality at all until the late 19th century. The industrial revolution enabled people to congregate in cities, and for social polarization to develop. But the degree of animus to a rational person today seems inexplicable, but part of the problems is the idea of living in a “zero sum game” world. Another concept mentioned early is “essentialism”. The Leopold and Loeb case in Chicago in the early 1920s may have contributed to hysteria (the play “Never the Sinner” by John Logan, which I saw in Minneapolis in early 2001.
The KU source is interesting; I earned a MA in math from KU in 1968, right before going into the Army.