Nassau State Railway

After the Taunus Railway (Taunus-Eisenbahn) from Frankfurt reached Wiesbaden in 1840, a private company was founded to continue the line along the Rhine. This was originally called the Wiesbaden Railway Company (Wiesbadener Eisenbahngesellschaft); from 1853 it was called the Nassau Rhine Railway Company (Nassauische Rhein Eisenbahn-Gesellschaft); and after 1855 it was called the Nassau Rhine and Lahn Railway Company (Nassauische Rhein- und Lahn Eisenbahn-Gesellschaft). The company was given a concession on 23 June 1853 by the Duchy of Nassau for the construction of the Nassau Rhine Valley Railway from Wiesbaden to Rüdesheim and Oberlahnstein. On 31 March 1857, this was followed by the concession for the Lahntal railway from Oberlahnstein to Wetzlar.

Only parts of the 188 kilometres of lines covered by the concession were completed due to insufficient funding. Therefore, on 14 October 1858, the Duchy of Nassau withdrew the company's concession and took over operations on the lines. The state formally took over the concession on 2 May 1861 on these lines:

30 km of the Rhine Valley Railway from Wiesbaden via Biebrich to Rüdesheim

21 km of the Lahntal railway from Oberlahnstein to Nassau.

On 20 November 1861, the company was reconstituted as the Nassau State Railway.

The Nassau State Railway completed the 56.6 km long gap in the Rhine Valley line between Rüdesheim and Oberlahnstein on 22 February 1862. The remaining 78 km of the Lahntal railway to Wetzlar was completed in three sections on 10 January 1863. This work was directed by the railway surveyor and engineer, Moritz Hilf.

With the end of the Duchy as an independent state as a result of the Austro-Prussian War, the Nassau State Railway was absorbed by the Prussian State Railways.

An attempt by the Rhenish Railway Company, to take over the Nassau State Railway and to operate the planned extension along the Rhine failed because of the demands of the Prussian state. Since Prussia's budget was strained by the war, it made the sale of the railway conditional on the simultaneous takeover of the loss-making Rhine-Nahe Railway Company. The Rhenish Railway Company was not willing to take over the Rhine-Nahe Railway Company, which would have undermined the profitability of its Eifel line, then under construction.

The Prussian State Railway preserved the organisation of the former Nassau State Railway and it was initially an independent division, based in Wiesbaden. Following the nationalisation of the Prussian private railways, its assets were incorporated in 1880 in the Prussian State Railway's Frankfurt am Main division.