J. Edgar Hoover was possibly the most powerful non-elected person in modern American history. As FBI director from 1924 through his death in 1972, he used the tools of state to create a personal fiefdom unrivaled in U.S. history. He ruthlessly rooted out real and perceived threats to the United States, from bank robbers to Soviet spies to civil rights groups, calling Martin Luther King, Jr. “the country’s most notorious liar.” But Hoover was more than a one-dimensional tyrant and schemer who strong-armed the rest of the country into submission; he was a confidant, counselor, and adversary to eight U.S. presidents, four Republicans and four Democrats.

Today’s guest is Beverly Gage, author of “G-Man: J. Edgar Hoover and the Making of the American Century.” We explore the full sweep of Hoover’s life and career, from his birth in 1895 to a modest Washington civil-service family through his death in 1972. Hoover was not above blackmail and intimidation, but he also embodied traditional values ranging from a fierce view of law and order to anticommunism, attracting him the admiration of millions of Americans. He stayed in office for so long because many people, from the highest reaches of government down to the grassroots, wanted him there and supported what he was doing.