The Mexican-American War is largely overshadowed by historians of the War of 1812 and the Civil War. This conflict demands an in-depth examination as a unique historical event. Scholars of the Mexican-American War have largely limited their approach to underscore how social and political relations, among American military and political elite, shaped the conflict as a causeway to the American Civil War. To better understand the Mexican-American war it is necessary to understand it through the experiences of those volunteer solders living during this conflict. In addition, understanding the role the environment played in shaping the social and political relations between Volunteers and regular soldiers, as well as their own understanding of national duty, is essential to recognize this conflict as more than simply a forerunner to the American Civil War. Thus, I examined primary journals, notes, letters as well as secondary historiographies to examine the relationship between environmental impact and Volunteer solders. This paper explores the ways shifting social and geographical environments, throughout the war, sparked conflicts between Volunteers and the regular forces, as well as the Volunteers’ conflicting ideas about national duty. The relation between the environment and the Volunteer’s action is clear in this paper and as such should be expanded upon in further research