After the Taunus Railway (Taunus-Eisenbahn) from Frankfurt reached Wiesbaden in 1840, a private company was founded to continue the line along the Rhine.
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.
[1] 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.