Since 1935, the Federal Bureau of Investigation has been America's national crime-fighting and counter espionage agency. From its headquarters in Washington and under the guidance of legendary director, J. Edgar Hoover, the agency built up a formidable reputation. Its history includes the G-Man era, the interception of Nazi agents in World War II, the hunting of communists in the 1950s and its role in the post-Cold War world. As the 20th Century drew to a close, the old simplicities of keeping America's Home Front secure against easily identifiable external threats had been succeeded by a more complex world of terrorism and drug trafficking. But there is no doubt that the FBI will continue to adapt to the challenges of the modern era.