such as the Berg-Mark Railway Company. Following the unification of Germany in 1871, attitudes changed in Prussia; Otto von Bismarck, in particular, pressed for the development of a state railway system. The railway was seen as having great military-strategic importance. Numerous ways were tried in order to create a common, German state railway. This was finally achieved during the inter-war years (1918–1939): in accordance with the Weimar Constitution the Deutsche Reichsbahn was founded. Prior to that, there were the following early and significant approaches to the creation of national "state railways" (Staatsbahnen): In Baden an "Act Concerning the Construction of a Railway from Mannheim to the Swiss Border near Basle" was passed on 29 March 1838 and announced on 2 April 1838. Several other acts followed that dealt with the financing, forced acquisitions, the establishment of a railway division and operating regulations. In Württemberg King William I announced on 18 April 1843 the "Act Affecting the Construction of Railways", according to which railways were to "be transferred to the administration of the state or built at the cost of the state". Apart from the state railways the construction of other branch lines was left to private concerns. However, relatively few private railways were built in Württemberg. In Bavaria the private Munich-Augsburg Railway Company began railway construction in 1839 and opened its route from Munich to Augsburg on 4 October 1840. The period of the Bavarian state railways began with the nationalisation of the Munich-Augsburg line in 1844. The Royal Bavarian State Railways began by building the Ludwig South-North Railway from 1844 to 1853; a line 548 kilometres long between Hof and Lindau. The Frankfurt National Assembly advised on the constitution of a German Empire as a federal state in 1848/1849. In doing so, they considered nationalising the railways and placing their management under the imperial government in order to strengthen the power of the empire. The Länderbahn era (1871 to 1920) German unification in 1871 stimulated consolidation, nationalization into state-owned companies, and further rapid growth. Unlike the situation in France, the goal was support of industrialization, and so heavy lines crisscrossed the Ruhr and other industrial districts, and provided good connections to the major ports of Hamburg and Bremen. By 1880, Germany had 9,400 locomotives each annually pulling 43,000 passengers or 30,000 tons of freight, and forged ahead of France Prussia nationalized its railways in an effort both to lower