In 1908, Charles Bonaparte (1851–1921), the attorney general for President Theodore Roosevelt (1858–1919), started the Federal Bureau of Investigation (FBI). Its aim was to investigate federal crimes for the Department of Justice with a small force of federal agents. J. Edgar Hoover (1895–1972), director of the FBI from 1924 until his death in 1972, created the FBI's most lasting image as a bureau of dedicated sleuths.

The first comic strip about an FBI hero was Secret Agent X-9 (1934), created by detective fiction (see entry under 1930s—Print Culture in volume 2) writer Dashiell Hammett (1894–1961). Pulp magazines (see entry under 1930s—Print Culture in volume 2) of the era were soon full of exciting (and some very unlikely) FBI agent adventure stories.

The bureau's hard-nosed government men (nicknamed G-men) were first featured on film as heroes in G-Men (1935), starring James Cagney (1899–1986; see entry under 1930s—Film and Theater in volume 3). Other...