Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
Transportation improvements in the nineteenth century loom large in the historiography of the profession during the twentieth century. This article describes the ongoing construction of a historical geographic information systems (GIS) transportation database designed to provide new insights into the impact of the transportation and communications revolution in the continental United States by providing evidence on the spatial dimensions of those changes over time. It also reviews some preliminary findings and reinterpretations based upon these data.