Before there was the FBI, there was the BOI, the Bureau of Investigations. J. Edgar Hoover was the director of the BOI in 1924 and was a founder of the FBI in 1935.
Born on New Year's Day, 1895, Hoover received his law degree in 1917. During WWI, he found work with the Justice Department, became head of the General Intelligence Division which morphed into a position with the BOI in 1921. President Calvin Coolidge named him head of that agency in 1924 after the previous head was implicated in fraud.
In the 1930's, a rash of bank robberies tested his power. Because of bank foreclosures on farms and homes, these criminals became folk heroes of sorts among the common man, making their apprehension even harder. The BOI could become involved with these crimes when the thieves took stolen cars across state lines, a federal offense. After a botched attempt to capture of John Dillinger in Manitowish Waters, WI, left a civilian and an agent dead, but the culprits free to steal another day, Dillinger became a bit of an obsession with Hoover. Nobody makes fools out of the BOI and goes unpunished. Hoover only felt vindicated when Dillinger was shot down in front of the Biograph Theater in 1934.
Dillinger's death, along with the capture of many other high-profile outlaws finally brought Hoover the recognition he felt he deserved. The Bureau's powers were widened and it was renamed the Federal Bureau of Investigations, which is what it remains today.
Almost from the very start, Hoover was accused of overstepping his bounds. He would investigate people based on their political beliefs instead of any criminal activities. Under his leadership, the FBI kept tabs on many people for their possibly radical beliefs. Cointelpro, a program he developed in the mid-50's, was involved in illegal wire-tapping, burglaries and planting forged documents, among other things. The program became public in 1971 and was abolished after being declared unconstitutional.
Hoover did many good deeds also. Under him, the FBI was depository to the largest collection of fingerprints in the world. The FBI's evidence lab was expanded and became a high-tech effective crime fighting tool. Because of his leadership, he's also been hailed as the reason why the country was relatively free of sabotage or espionage during the WWII years.
Despite allegations that Hoover tended to abuse his power, both with criminals and his own agents, Hoover remained the bureau's head until his death in 1972. President's Truman, Kennedy and Johnson all considered firing him during their administrations, but the affect he could have on their political careers and those of their friends forced them to reconsider. In 1974, files were found containing dirt Hoover had collected on many political personalities. That's one way to obtain job security.
The FBI headquarters in Washington DC is named after Hoover. Due to the controversies during his rein as leader, it's been suggested that the building be renamed, but at this time, the name remains.