War reporting was censored during World War II; for example, citizens could not report on German U-boats off the coast of New England.
Obscenity: Up until roughly 1950, books, plays, and so forth were regularly banned by local government for obscenity. (For example, particularly interesting works would carry the tagline of "banned in Boston".) Currently, the U.S. definition of obscenity is extremely liberal, although Ashcroft et al. regularly pursue obscenity cases against pornographers, apparently to create fear in the industry.