Every nation involved in World War I published posters that justified the war to its citizens and encouraged them to help with the war effort. The United States, which was in the war for only a year and a half, produced more of these propaganda posters than any other nation.

The posters all used vivid images and patriotic slogans to inspire or, sometimes, to scare Americans. Some posters explained why America had to fight — for liberty or for “civilization.” Others encouraged men to join the army and navy and women to become nurses. Many posters asked Americans to buy Liberty Bonds — government loans that paid for the war. Even children were asked to help. The posters give a picture of the war, how it was fought, and what American society was like in 1918.