In this dissertation, I examine legal definitions of race within the United States and the representation and reformulation of these categories within U.S. literature. The substrate of this dissertation is a collection of American literary and legal texts from the 17th through the 20th centuries. I examine how these texts chronicle, represent, and often intentionally misrepresent individuals' attempts to subvert and even openly challenge delimited identifications such as ìmmigrant' or s̀lave.' Often these challenges are leveled against the normative identificatory organ of L̀aw,' that is, the judicial processes and legal decisions that establish and confirm these reductive identifications. The mode of the challenges I examine is movement, or literal mobility. When normative pathways of identification begin to fail, mobility gains importance as a means of transgressing, figuratively and literally, usually impermeable classificatory boundaries. The idea of mutable identity is almost a truism of modern Western thought. Less appreciated, however, is the connection between identity and location, and more pertinently, the coordination between movement and identity. This coordination is the first focus of my dissertation. In order to understand these identifications and mobile re-identifications, this dissertation examines the sets of conditions - historical, social, biological, and especially legal - that seek rigidly to classify individuals as well as the sets of conditions that enable mobile re-identification. Phrased in another way: this dissertation explores both the possibilities of literal transgression of identificatory boundaries as well as the execution of such transgressions. Alongside literary chronicles of these transgressions, I analyze a variety of legal texts that have promulgated and structured reductive methodologies of identification. Whether negotiating slavery, Jim Crow, segregation, or post-WWII immigration politics, the examined literary texts are distinctly concerned not only with the tensions of identity, but the manners in which mobility or transit can enable self-determination through re-identification. Conversely, the examined legal texts display the formulation and repeated revision of criteria of reductive identifications chronicled in the examined literature. The power of law to establish interpretive methodologies that reductively identify individuals is the second focus of my dissertation.