Grand Duchy of Oldenburg State Railways

Compared with the other states in the German Empire, Oldenburg's first railway line arrived relatively late.

In this sparsely populated and economically poor area, the construction of railways appeared for a long while to be unsustainable due to the financial costs.

In addition, the various ideas of its neighboring states, Hanover and Prussia prevented railway projects from coming to fruition for a long time.

In 1869 the east–west line from Bremen to Oldenburg was extended to what was then Prussian Leer in East Frisia by a line from Oldenburg to Leer with a junction to the Hanoverian Western Railway and, in 1876 by the section from Ihrhove to Nieuweschans with a junction to the Dutch Railways.

In 1897 the route from Jever to the harbour at Harle, opened in 1888 as the Jever–Carolinensiel railway, was finally taken over by the GOE.