John Dos Passos was one of a "war generation" of young novelists for whom World War I was a source of excitement and then disillusionment. The works of Hemingway, Cummings, and others illustrate this, but for Dos Passos the war became a preoccupation which lasted through most of his writing career. Like many other young novelists, Dos Passos saw the war as an ambulance driver. This gave him direct personal experience with war, which he later utilized in his novels. This study examines three works, First Encounter, Three Soldiers, and U.S.A., to show how Dos Passos reworked the materials of his personal experience each time for a different effect and to a different purpose. First Encounter is a generally direct rendering of Dos Passos' life as an ambulance driver. The central character, Martin Howe, is a sensitive and thoughtful observer much like the young Dos Passos. He embarks for France and the ambulance corps in search of adventure. During his period at the front he undergoes an initiation experience of uncertain nature, which gives him a more mature view of war. The novel is an immature and unsuccessful work, important only for the introduction of motifs which appear in later Dos Passos novels. In Three Soldiers Dos Passos imposes some sort of form on his material. He attempts to combine subjective reactions such as those of Martin Howe with a look at the war from a more distant perspective. There are three main characters, each representing a different level of perception about the war and the army. Dan Fuselli's opinions are all formed by what he sees in the movies; Chrisfield is just beginning to react independently; John Andrews is a highly perceptive musician who thinks for himself. Each struggles with the destructive force of organized military power, and in his own way is defeated. Only John Andrews retains a measure of independence. Dos Passos reinforces his theme with appropriate satiric techniques. U.S.A. is still another expansion of focus. Here the author sees war as part of a network of corruption and injustice which informs all of modern American life. Dos Passos uses the Newsreels, the Biographies, the fictional narratives, and the Camera Eye to relate the war thematically to big business' exploitation of labor and other instances of loss of individual freedoms. As in Three Soldiers Dos Passos is concerned with the struggle of the individual against the huge, impersonal "system." U.S.A. represents as well the most effective satire of the war and of the people who are attracted to it. One strong motif is the use of language as a "smokescreen" which conceals reality when used by unscrupulous people; both fictional and real figures are criticized for this, especially Woodrow Wilson.