To meet the challenge of mobilizing the nation for war in Europe, the Wilson administration took steps to silence dissent on the home front. In addition to a massive propaganda campaign to rouse public enthusiasm for the war, the government used the Espionage Act (1917) to silence anti-war publications and to arrest pacifists, political radicals, and others accused of making disloyal statements. The government’s campaign against dissenters was upheld in landmark decisions by the Supreme Court, supporting the imprisonment of hundreds of anti-war speakers, most notably the socialist leader Eugene V. Debs. While federal government repression encouraged similar laws at the state level as well as a wave of vigilante violence against pacifists and anti-war radicals, the arrests also led some free speech advocates to form the American Civil Liberties Union, one part of a wider campaign that sought amnesty for imprisoned dissenters.

The period of American neutrality during the first three years of World War I (1914-1917) was marked by widespread disagreement. Widespread propaganda advocated neutrality as well as intervention on either side. Propaganda advocating different positions nevertheless tended to use some of the same—often gendered and sexualized—imagery to solicit and channel American emotions. Once the US declared war, the creation of a state-sanctioned propaganda agency, The Committee on Public Information (CPI), produced a flow of information that was both intense and univocal in its support for the war. Meanwhile, legislative acts legalized censorship, enabling the Post Office, government at all levels, and even non-state actors to police speech, jail and attack pacifists, and limit dissenting publications. The widespread use of media to secure public consent for and participation in the war effort is an element of modern, total war. The media landscape was permanently changed. Propaganda moved through social channels and frequently targeted and depended upon women to both relay and follow its messages; after the war, largely as a result, women gained the vote. Other legacies were more negative. Some modernist writers and artists would denounce martial (ab)uses of language and to adopt new strategies (including irony) to undermine notions of linguistic and political certainties.