The Federal Bureau of Investigation (fbi), the investigative arm of the Department of Justice, was created in 1908 by Attorney General Charles J. Bonaparte over the initial opposition of Congress who feared political abuse of such powers.

During and after World War I, the fbi investigated draft resisters, violators of the Espionage Act of 1917, and alien residents suspected of radicalism. This kind of surveillance marked a shift away from criminal investigations toward individuals thought to be domestic security threats, a group including such diverse figures as Jane Addams and Fiorello La Guardia. Such misuse of the fbi's powers led to reorganization in 1924. The bureau received orders not to engage in wiretapping or to investigate the political activities of individuals. J. Edgar Hoover, appointed director, professionalized the bureau, placing appointments and promotions on a merit basis and developing new crime-fighting techniques.

Despite the ban on political surveillance, World War II and the cold war prompted a wide expansion of security investigations. Under the guise of national security the fbi amassed over thirty-five thousand linear feet of files on individual citizens. Following the death of Hoover and the Watergate scandal in which it was involved, Congress and the attorney general again issued guidelines designed to prevent such abuse. In the late 1970s the fbi shifted its investigations toward organized and white-collar crime.