This thesis examines war trauma in film; it is a comparative reading that aims to study the relationship between films made after the First World War in the 1920s and films made during and after the Vietnam War. I use thirteen focus film texts, some which explicitly engage with war and some that do not. This thesis will argue that the production of these particular films was inflected by the collective trauma that the wars produced in American society. There was not, for example, an explicit combat film made for seven years after the First World War and thirteen years after the Vietnam War. This gap, I will argue, is symptomatic of the cultural climate that existed after each war, but can also be understood in terms of the need for temporal space in which to assimilate the traumas of these wars. An engagement with recent debates in Trauma Theory will be utilised to explore this production gap between event and film, and to suggest that trauma exists not only within the narratives of these focus films but also within the production process itself. This thesis contributes significantly to recent debates in Trauma Studies. As it presents film history scholarship, First World War and Vietnam veteran experiences and archive newspaper research as compatible disciplines and uses the lens of trauma theory as a methodological thread and tool of analysis.