In recent times, the declaration of the prominence of the visual over other channels of communication has been persistent across several disciplines, including film studies, design, sociology, and literacy education (e.g. Bolter, 1991; Fransecky & Debes, 1972; Kress, 2005; Sartori, 1998; Messaris, 2012). It is within this loom of visuality that the concept visual literacy has been woven together throughout the twentieth century and beyond. This dissertation explores the mobilization of this concept through the last century and addresses the implications of its interdisciplinary and polysemic nature. By tracing the evolution of this term, as well as some of its correlates in English, I map the concept of “the visual as a literacy.” In order to do this, I first completed a comprehensive search of available databases for all uses of “visual literacy” in English, in the process compiling a working bibliography of 2400 documents. Subsequently, I created a full-text database of 330 representative documents I deemed most central to the mobilization of visual literacy. I employed text visualization approaches combined with close reading to understand trends and patterns in my datasets. Beyond using available tools for text visualization, I also worked with a team to design and program a tool specifically for analysis of my full-text corpus: The Glass Cast (Peña, Juárez, Dobson, & INKE Research Group, 2016). This tool is a plug-in for the open- source reference management software Zotero. It allows researchers to visualize relationships between documents in a bibliography over time. In itself this tool is a unique contribution to scholarship and a key outcome of this study. Findings of this research included the revelation of a rich history of visual literacy dating to 1939, the identification of three virtually independent historical avenues, or waves, of mobilization of visual literacy, and the coexistence of at least two confounding understandings of the concept. Ultimately, I address these two different understandings in an attempt to inform the work of educators invested in the topic.