The building of the line was preceded by many years of negotiations between the three sovereigns states through which the planned line ran: the Free City of Frankfurt, the Duchy of Nassau (of which Wiesbaden was capital) and the Grand Duchy of Hesse for the section in Mainz-Kastel, a suburb of Mainz on the eastern bank of the Rhine.

A consortium to build the railway was established in 1835[2] under the leadership of the two Frankfurt banks Gebrüder Bethmann and Rothschild.

Nevertheless, the final concession was not approved until 1838: by the City of Frankfurt on 8 May, by the Grand Duchy of Hessen on 11 May and by Nassau on 13 June.

The first stage was opened on 26 September 1839 from the Taunus station in Gallusanlage (now Willy-Brandt-Platz), Frankfurt, to the then small Nassau town of Höchst am Main by the Mainz masterbuilder, Ignaz Opfermann.

Carting companies and drivers of the region, fearing for their income undertook an attack in Mainz-Kastel, on the line and damaged the tracks.

[4] The director of the company from 1840 to 1852 was Johann Adam Beil, a Hessian privy councillor and former Frankfurt senator.

Originally the railway operated six locomotives from the factory of George and Robert Stephenson, 87 carriages and 44 wagons.

After its repair and the resumption of operations, it re-established its former importance, with increasing freight traffic on the line, especially on the section from Kostheim junction to Wiesbaden East station.

In the early 1990s, the long-distance traffic on the Taunus Railway was operated only by single IC commuter trains between Frankfurt and Wiesbaden, which was eventually discontinued for lack of demand.

In 1995, the Rhein-Main-Verkehrsverbund (Rhine-Main Transport Association, RMV) replaced the FVV, and simultaneously introduced the new Regional-Express line 90 (the former express trains were now rebranded as Regional-Expresses, abbreviated as RE), which used the Taunus Railway from Wiesbaden Central Station to Kostheim junction.

The western entrance to the Frankfurt main freight yard (Hauptgüterbahnhof) was located at line-kilometre 6.1.

The Taunus railway crosses the Schwarzbach (line-kilometre 14.8) about 100 metres northeast of the Hattersheim (Main) station on a rather nondescript two-arch sandstone bridge.

Mainz rail bypass meets the Taunus railway at Kostheim junction (line-kilometre 30.8).

It stands side-gabled to the south of the tracks and was put into operation in 1904 together with the Mainz rail bypass.

[12] A few metres east of the signal box was a listed building pedestrian bridge, also from 1904,[13] that crossed the tracks.

A brief period of operation with long-distance trains, which, in order to shorten the travel time, only stopped in Wiesbaden-Biebrich, bypassing Wiesbaden Hauptbahnhof, was discontinued because of insufficient demand.

On 3 August 1840 a 1.5 kilometre-long branch line was opened to Biebrich, which was operated by horse-drawn traffic until 14 May 1872.

It was particularly important in the early days for rail freight operations and was in the immediate vicinity of the customs office on the Rhine bank.

With this act of sabotage Mainz merchants attempted to block access to the free port of Biebrich to remove the competitive advantage of the railway.

It resembled the central buildings of the main stations in Wiesbaden and Frankfurt, which had also been planned by Ignaz Opfermann.

The IC commuter trains in the late 1990s consisted of 2 to 3 carriages, hauled by a class 141 locomotive.

As early as the mid-1970s, prior to the inauguration of the S-Bahn, trains were also operated by class 420 electric multiple units.

These replaced the Regional-Express services operated by Deutsche Bahn, so that between Koblenz and Wiesbaden, all stops are served hourly.