19th century America is shaped greatly by territorial expansion into Native American lands. A famous painting which represents this process is called American Progress by John Gast. This study argues that the display of power between the settlers and the Native Americans in the painting mirrors the dominant discourse on 19th century westward expansion. So, the analysis is concerned with how the settlers are constructed, how the Natives are displayed and how this results in a power hierarchy. These findings are then compared to 19th century discourse on the westward movement. The analysis is guided by the methodological tool of Foucauldian discourse analysis. The analytical steps are informed by the two American Studies scholars Angela Miller and Martin Christadler. The research is based on pragmatism with a leaning towards constructivism. This study finds that American Progress contrasts civilisation and nature in similar ways as this dichotomy is established in the discourse of the 19th century. Westward expansion in the painting and in 19th century discourse is justified by constructing the Natives as godless and the settlers as godly. The difference in brightness in American Progress supports the dichotomies of civilisation and nature as well as godliness and godlessness.