The Prince William Railway Company (German: Prinz-Wilhelm-Eisenbahn-Gesellschaft, PWE) was the first horse-drawn railway in Germany. It was founded as the Deil Valley Railway Company (Deilthaler Eisenbahn Aktiengesellschaft) in 1828 and renamed in 1831. It built a 820 mm (2 ft 8 9⁄32 in) narrow gauge line that ran for a Prussian mile (7,532 metres) along the Deilbach valley from a point near Kupferdreh Old Station in Hinsbeck, a suburb of Kupferdreh (now part of Essen), to Nierenhof near Langenberg (now part of Velbert). This route is now part of the Wuppertal-Vohwinkel–Essen-Überruhr railway and served by Rhine-Ruhr S-Bahn line S9 trains.
On 20 September 1831 the railway was opened by Prince William, the brother of the King of Prussia at the time, and renamed in honour of the prince. It operated as a horse-drawn railway carrying coal until 1844, but from 1833 it also carried passengers. In 1847, it was converted to standard gauge, extended north to Steele Süd and south to Vohwinkel (in Wuppertal), converted to steam operation and renamed the Steele-Vohwinkler Eisenbahn.
Friedrich Harkort had an early interest in improving the transportation of coal from the Ruhr in the Bergisches Land to Wuppertal. He therefore visited England to study the first railway projects and wrote in 1825 in the journal Hermann an article on "Railways". He sought the interest of donors to realise such a project. He finally found interest mainly in the mining trades in the Ruhr. In 1826 he had built a small test track, as a monorail following a design of the Englishman Henry Robinson Palmer. This was a precursor to the Wuppertal Schwebebahn finally built 74 years later. On 9 September 1826 he advised the Elberfeld Council two routes for the construction of such a railway from Elberfeld via Uellendahl, Horath and Herzkamp to Hinsbeck or from Elberfeld via Horath to Langenberg. In 1826 and 1827 surveying were carried out in these districts.