This paper will make clear how and in what extent the railway policy of the Prussian government exercised its influence on private railways in Rhine-Westphalia. The Berg-Mark Railway with some local lines, founded by bankers and manufacturers in Wuppertal, expanded its network of lines to be one of the greatest railways in Germany within a half century. It was so closely linked with the State that the Minister of Commerce, August v.d. Heydt, initiating the policy of railway nationalization, had been a main member of the board of directors. In 1850 when the Berg-Mark Railway could not raise the capital to build a new line, the State made a financial support with a conditional contract that the former should hand its administration over to the latter. Though this measure robbed private shareholders of control over the running of the company, they were rather willing to accept it, because they were of opinion that skillfull managers and engineers were merely obtainable under the name of officials. This type of railway enterprise, owned by shareholders and managed by the State, might be, in a sense, a suitable form in Germany. The State intervention was made, in some extent, by military needs to facilitate the defence of the west but also in view of the economic significance of the Ruhr with coal fields and the Western industries. Both the State and the Western had the common interest that their economic activities were hampered by economic-geographic standing-points of the Rhine-Westphalia, which was in closer touch with Holland and Belgium than Berlin.