A review by graywacke
G-Man: J. Edgar Hoover and the Making of the American Century by Beverly Gage

informative

4.5

Hoover is an American villain, a scapegoat for everything wrong with America in the 1950s and the 1960s. He was also a dedicated civil servant for 40+ years, leading the FBI from 1924 until his death, a weak before the arrests that became Watergate. He was appointed under Cooleridge, and supported by presidents Herbert, FDR, Eisenhower, Johnson, and Nixon, and he was tolerated by Truman and Kennedy. He had a 90%+ approval rating when Nixon, a close friend of his, was elected. 

Involved in the Palmer raids targeting Communist radicals in 1919, he survived the backlash and cleaned up the FBI. But he willingly helped FDR on illegal counter-intelligence, and spying, and only extended his surveillance of American extremists, and any leading liberal figures. A hard conservative, he was most worried about anything that threatened the status quo - which meant the KKK, but also civil rights leaders and anyone wrestling with non-violent southern racism, something he quietly supported (!). He even wire tapped MLK, finding all his private sexual exploits. He also prosecuted government homesexuals, by open policy, even though he, himself, was quietly gay. But no one knew all he was doing. 

When Watergate broke, and congress started investigating into the FBI, post-Hoover, with unexpected openness by the new head of the FBI, all the surveillance Hoover had run came to light, and he went from a hero's funeral, to, almost immediately, and posthumous American villain. 

tldr: this is an excellent biography of a difficult, unpleasant, but important American figure.