From the 1910s to the end of World War II, visual representations have been increasingly used in newspapers, magazines, pamphlets and official reports in the United States as a way to convey aspects of economic and social facts to a wider audience. A number of historians have shown that this movement toward visualization, which originated in various projects within social science departments and among social reformists, culminated during the years of the Great Depression when the Roosevelt administration used extensively photographs as a way to promote its economic policies. The most studied of these projects within the Roosevelt administration is the Historical Section of the Farm Security Administration, which hired photographs such as Walker Evans, Dorothea Lange and Arthur Rothstein and sent them to the field to document the living conditions in rural America. Indeed, previous works on visualization have mostly focused on photographic representations of economic and social facts, as opposed to other types of visualization such as pictorial statistics, maps and drawings, which were equally important in the period. In addition, while these accounts focused on the artistic and communicational values of the resulting images, they did not investigate in depth the origins of this movement toward visualization in the works of economists and social scientists. Historians of social sciences -- especially economics -- have not paid attention to the visualization of social facts either because their work most often deal with the scientific and academic aspects of the discipline they study, therefore neglecting issues of communication and popularization. Indeed, contemporary social scientists tend to undermine the role of visual representation in their discipline because they do not consider visualization as constitutive of scientific knowledge, hence limiting its use to pedagogical purposes.