James Montgomery Flagg ( 1877-1960 ) was one of the many artists who created posters for the war effort. In his autobiography aptly titled Roses and Buckshot , he describes his contribution to the war effort:

One of the many Flagg posters in the Library's collection is "Tell That to the Marines!," which was painted on the New York Library steps in World War I. Flagg reflects on this painting in his autobiography:

Another wartime innovation for which I was responsible involved the phrase "Tell That to the Marines!" It had implied that the Marines are so gullible they would believe anything. My poster of that title made it a fighting battle cry. I repainted this poster on a huge canvas on the steps of the Library with my model posing, and a platoon of Marines with bayonets marching about.

The Pritzker Military Library has over 15 of Flagg's creations in its collection, including a number of posters that feature his famous renditions of Uncle Sam. The most famous of his Uncle Sam posters entitled I Want You for U.S. Army, which is a highlight of the Library's current exhibit, sold more than 4 million copies during World War I and almost half a million during World War II. It was originally designed as the cover for Leslie's Weekly with the caption: "What Are You Doing for Preparedness?" and was a significant departure from the earlier depictions of Uncle Sam. It continues to be used today.

Another popular motif used by Flagg and the other artists who contributed to the war effort is the female icon which is generally referred to " Columbia ," " Liberty ," "Miss Liberty ," or "the Goddess of Liberty." Both Flagg and Howard Chandler Christy depicted Miss Liberty as an attractive young woman of the period.