Mapmaking and Printing
Technological advances in papermaking and printing which permitted quick and inexpensive reproduction of maps greatly benefited railroad cartography. Before the introduction of these new techniques early in the nineteenth century, maps were laboriously engraved, in reverse, usually on copper plates, and printed on hand presses. Although the results were excellent, this slow and costly process could not keep pace with the demand for railroad maps. The process of lithography which was invented in 1798 by Alois Senefelder of Bavaria, came to America at an opportune time, just as the first railroad charter was being granted in 1815. This invention revolutionized map printing and provided the means for inexpensive map reproduction. Within two years after William and John Pendleton established the first important lithographic printing house in Boston, in 1825, their firm was printing railroad surveys and reports for the earliest New England railroad companies.
Even after lithographic printing in map production became common, engraving was used for many years for the finer and more limited works. As late as 1848 Peter S. Duval of Philadelphia engraved map plates of Virginia for Claudius Crozet, principal engineer to the Commonwealth.
Technical advances were quickly adapted to map printing. The transfer process eliminated most of the laborious procedure of drawing on stone in reverse. It allowed an illustration or a newly drawn map, using specially prepared paper and ink, to be transferred directly to a stone or a zinc plate. The early use of "zincography" in America, in 1849, is credited to P.S. Duval's Swiss shop foreman, Frederick Bourquin. Zinc plates were adaptable to the rotary steam power press, which was first installed by Duval in his Philadelphia lithographic establishment.
Another important printing process, cerography, or wax engraving, was introduced in America by Sidney Edwards Morse, whose father, Jedidiah Morse, published the first geography book in the United States, Geography Made Easy, in 1784. The process was first used in 1839 for Morse's "Cerographic Map of Connecticut" and in 1842 for the Cerographic Atlas of the United States. This was an ingenious method of making a mold from which a printing plate was cast. On a thin layer of wax applied to a copper plate, lines and symbols, and later type, were inscribed or impressed. Through the means of an electroplating process, a relief mold was produced from which single sheet maps were printed. The process was kept secret by Morse. It became more widely used after Rand McNally introduced its "wax engraving process" in 1872.
From the 1870s through the first four decades of the twentieth century, this method of printing, sometimes called "relief line engraving," became very popular with large map printing houses in the United States. The firm of George F. Cram and Company, well known for its railroad maps and other geographic publications, adopted the process in the 1880s with the introduction of its Universal Family Atlas of the World. Matthews-Northrop and Company and Poole Brothers also used this method for printing their numerous railroad maps. Multicolor printing, the development of photolithography, and the offset press further accelerated railroad map production and greatly reduced prices.
Color lithography to distinguish regions and administrative divisions on maps was introduced as early as the 1850s. Color to accentuate the many lines of intricate railroad networks, however, continued to be manually applied to many maps at the end of the century.