These railroads were built by the iron and coal companies in the early 1840s, in anticipation of connecting with the B&O Railroad and the Chesapeake and Ohio Canal, both then under construction to Cumberland. Some of these standard gauge mine roads owned and operated their own equipment, while others were operated with early B&O motive power and rolling stock. By 1870, all of the lines were absorbed into the Cumberland & Pennsylvania Railroad, which was itself absorbed into the Western Maryland system.