His experiences at the front as one of eight artist-correspondents with the American Expeditionary Force in Europe were a turning point for the artist. Dunn’s interest in commercial illustration declined on his return to the United States. Instead, the artist envisioned working for several years for the War College committing to canvas his sketches of the battlefields of Europe. Unfortunately, demobilization occurred at a rapid pace, and Dunn’s project was rejected. It became the big heartbreak of his life. However, Dunn was able to salvage part of his ambitious plan; in 1927, he began to paint covers with military themes for The American Legion Monthly magazine. The majority of Dunn’s war sketches are now housed at the Smithsonian Institution in the National Museum of American History in Washington, D.C.