The mountain contour of the country and this same grouping of the important centers of population have been the chief influences in the location of the railways. Owing to the absence of navigable streams, the mere possibility of Mexico’s industrial and of even her true national development had to wait upon the coming of the railways. The first line was that completed in 1872 by English capital between Vera Cruz, the chief port of the Gulf of Mexico, and the City of Mexico, some 400 miles inland and a mile and a half above the level of the port. This “Mexican Railway” touches the groups of cities along the old Spanish highway, and gave them an industrial primacy which was unchallenged until the very last years of the Diaz peace. After the building of this first line railway construction turned to follow the great natural avenues laid out by the mountain valleys. There were, as we have seen, two main valleys, that between the Eastern and Western Mother ranges, and that to the east of the Eastern chain. Looking at a map of Mexico, the most casual observer is struck by the fact mentioned more than once by Mexican revolutionists, that both these valleys lead directly to the heart of the United States. The railroads which were built there might indeed be taken to have been built to drain Mexico’s resources into the United States. But it was only because these roadbeds had been laid out by Nature herself that the lines came to be built there, with the inevitable result of increasing immeasurably the importance of the United States to Mexican development. One early Mexican president (Sebastian Lerdo de Tejada, 1872-76), in fact, refused to allow these obvious roads to be built, explaining, in a much-quoted phrase: “Between the weak and the strong, let the desert remain.” The roads were both built by American companies under President Diaz, the Mexican National on the east, the Mexican Central on the west. They had a mighty part to play in the modernizing of Mexico, and in her development through the trade in the minerals and in the building of such industries as followed them. Throughout their history to the present, they have been of far greater importance to Mexico than to her allegedly covetous northern neighbor. After these lines were built, others came, to follow the mountain valleys. One went from Mexico City westward to Guadalajara, tapping the rich Valley of the Lerma, the granary of Mexico. Narrow gauge lines twisted through the rich states of Mexico and Michoacan, lines which when modernized and extended in some future time will open agricultural and mining territory comparable to anything yet known to commerce and Mexican industry. Another line found its way to Oaxaca, deep in the mountains to the east and south of Mexico City. Others followed the seacoast to the Isthmus of Tehuantepec, and crossed that narrow, shallow neck of land to the Pacific.