In this course we will explore how the U.S.-Mexico border transformed from a “line in the sand” to a place of increasing physical presence. The 20th century brought customs stations and fences to channel bodies through a federally regulated space. Over time, fences and check points transformed into walls, buildings, and a network of roads built to control the movement of mobile nature: people, animals, and pathogens. Using both primary and secondary texts, documentaries, and news articles, we will learn why federal agencies created an unnatural border and how it has affected immigration and the environment in the borderlands. This course counts as elective credit towards the History major.