The postcard that pitted the ACLU against the FBI

The recently released Federal Bureau of Investigation file for former head of the American Civil Liberties Union Roger Baldwin document numerous times the groups came into conflict with each other. One notable incident, related to the Bureau’s wartime “Postal Censorship” program, led to a testy exchange between Baldwin and FBI Director J. Edgar Hoover after the Bureau investigated the writer and pioneering Libertarian Rose Wilder Lane over her comments on a postcard.