A railway company was created in 1891 with the aim, to connect the port of Tanga at the Indian Ocean with the Lake Victoria by passing south of the Usambara Mountains. 1,000 mm (3 ft 3 3⁄8 in) gauge was chosen. Since June 1893 the line advanced from Tanga inland. Due to undercapitalization the company had to be taken over by the state in 1899. Thereafter the line was run by the Ostafrikanische Eisenbahngesellschaft (East African Railway Cooperation), a company which had been created to build and operate the Tanganyika Central Line (Zentralbahn) from Dar es Salaam to Kigoma. Between Pongwe and Ngommi on the Usambara Railway there was a double hairpin turn.
On 26 September 1911 the track reached Moshi at Mount Kilimanjaro after 351.4 km (218.3 mi). Traffic on the whole line commenced on 4 October 1911, the official inauguration took place on 7 February 1912. In 1914 one train ran from Tanga to Buiko and back daily and on two days of the week the service continued to and from Moshi. The trip over the entire distance took 14 hours 40 minutes.
From 4 June 1912 – 12 May 1913 the line was renamed Nordbahn (Northern Railway) for a short period. The extension to Arusha was already planned and money provided but was not built due to the start of World War I.
The British mandate, which took over Tanganjika from the Germans, connected the Usambara Railway between Moshi and Voi with the Uganda Railway in Kenya and extended it 1929 to its current termination point Arusha.
After Tanzanian independence the Tanzania Central Line and the Usambara Railway were connected between Mruazi and Ruvu. During the East African Community, which covered Kenya, Uganda and Tanzania, the Usambara Railway belonged to the East African Railways (EAR). This community was dissolved in 1977 and the Usambara Railway became part of the Tanzania Railways Corporation which was taken over in 2007 by an Indian investor.
Under the German rule in 1913, the Usambara Railway operated 18 locomotives, 31 carriages and 199 trucks with 562 employees (of which 35 were Europeans).
After construction of the connection to Voi, traffic between Arusha, Moshi and the coast was directed to the port of Mombasa and the eastern part of the Usambara Railway was reduced to a local service. The passenger traffic was handled with four DMUs during this time. Passenger trains operated on the line into the 1990s.
- Helmut Schroeter: Die Eisenbahnen der ehemaligen deutschen Schutzgebiete Afrikas und ihre Fahrzeuge = Die Fahrzeuge der deutschen Eisenbahnen 7. Frankfurt 1961.