The censorship of the First World War came from three main directions, official censorship by the American government, by the American military, and the self-censorship of American soldiers themselves. Military censorship during the Great War was thorough and invasive. It began at the training camps and only intensified as the doughboys moved to their ports of embarkation, and then to the Western Front. Private letters were opened, read, censored, and even destroyed. The doughboys themselves greatly aided the military by self-censoring their own writing. Few letters were ever discovered that contained information of a truly military nature.

Censorship on the homefront also reached unprecedented levels. President Wilson’s Committee on Public Information waged a war against anything that it determined not to be "100% American." This new organization attempted to censor out of the public discourse any item that might be seen as pro-German. German: literature, philosophy, books, music, newspapers, words, dog breeds, foods, and flags were all to be wiped from the nation. The C.P.I. enlisted an army of untrained volunteer foot soldiers, the American Protective League, to do its bidding. The APL wreaked havoc across the nation trampling the civil rights of any group that got in its way.

The censorship of wartime was then extended into peacetime, with devastating consequences. The Spanish Flu had begun to spread during the war, and the news of its very existence was determined to be a threat to the war effort. It was feared that news of the deaths of hundreds of thousands of Americans would embolden the Germans to keep on fighting, so President Wilson said nothing of it. Panic spread across the land. Over 675,000 Americans would die.