The FBI

The Federal Bureau of Investigation, founded in 1908, is the principal federal law-enforcement agency and domestic intelligence service of the United States. It investigates federal crimes, from organized crime and public corruption to terrorism, and it serves as the nation's shield against threats at home.

For nearly half a century the FBI was J. Edgar Hoover. He built it into a modern, scientific crime-fighting force — pioneering fingerprint files and forensic labs and pursuing the gangsters of the 1930s — and made himself one of the most powerful and feared men in Washington.

Under Hoover the Bureau also became an instrument of political surveillance. Its COINTELPRO programs spied on, infiltrated, and tried to discredit civil rights leaders, antiwar activists, and others Hoover deemed subversive — including a notorious campaign against Martin Luther King Jr. The abuses, exposed in the 1970s, led to reforms and term limits on the director.

Today the FBI balances its dual role as both a law-enforcement agency and a domestic intelligence service, central to counterterrorism and counterintelligence — and recurrently at the center of debates over surveillance, civil liberties, and political independence.