This line shapefile represents the railroad network of the United States in 1840. This layer is part of the Railroads and the Making of Modern America project. This project seeks to document and represent the rapid and far-reaching social effects of railroads and to explore the transformation of the United States to modern ideas, institutions, and practices in the nineteenth century. University of Nebraska. Lincoln. (2006). Railroad System, United States, 1840. University of Nebraska Lincoln. Available at: https://purl.stanford.edu/st852jv1039. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.