The organisation was responsible for a huge range of engineering projects both in Nazi Germany and in occupied territories from France to the Soviet Union during the Second World War.

From 1943 until 1945 during the late phase of the Third Reich, OT administered all constructions of concentration camps to supply forced labour to industry.

[2] The autobahn concept had its beginnings in the efforts of a private consortium, the HaFraBa (Verein zur Vorbereitung der Autostraße Hansestädte-Frankfurt-Basel), initiated during 1926 for the purpose of building a high-speed highway between northern Germany and Basel, in Switzerland.

He made it a vastly more ambitious public project and the responsibility was given to Fritz Todt as the newly named Inspector General of German Roadways.

[citation needed] Initially, the Autobahn project relied on the open labour market as a source of workers.

[citation needed] Between 1939 and 1943, in contrast to the period from 1933 to 1938, fewer than 1,000 km (620 mi) of roadway were added to the Autobahn network.

[citation needed] Fritz Todt died in an aeroplane crash on 8 February 1942, soon after a meeting with Hitler in East Prussia.

At the beginning of 1943, in addition to its continuing work on the Atlantic Wall, the organisation also undertook the construction of launch platforms in northern France for the V-1 flying bomb and V-2 rocket.

During the summer of that year, German war efforts became increasingly defensive, and the organisation was directed to construct air-raid shelters, repair bombed buildings in German urban areas, and construct underground refineries and armaments factories, also termed Project Riese.

Speer's concerns, in the context of an increasingly desperate Germany, in which all production had been severely affected by materials and manpower shortages and by Allied bombing, ranged over almost the whole of the German war-time economy.

Up to about 1942, the construction companies dominated the OT, but after Speer became its director, the government's control of the organisation increased through standardised contracts and uniform pay scales.

[9] The organisation of OT contractors was standardised through instructions issued by Wirtschaftsgruppe Bauindustrie, the German construction industry association.

A new HQ in Berlin, Amt OTZ, was created with Ministerialdirigent Franz Xaver Dorsch as chief of staff.

The role of the NSKK began in 1938, with the NSKK-Transportbrigade Todt in charge of motor transportation for the construction of the Siegfried Line.

Foreign drivers were, however, recruited into the Legion Speer, since they – as aliens – could not be members of the NSKK, which was a sub-organisation of the Nazi Party.

Many went on to serve in the post-war British and U.S. Labor Services in occupied Germany before emigrating to Britain, Australia, Canada and the United States.

Several SS guards and local collaborators were sentenced to prison and death after the war in trials in Belgrade and Oslo.

The head of the responsible OT unit for Scandinavia, Willi Henne, was extradited to the Soviet Union and served 10 years as a prisoner of war before returning to Hessen in West Germany.

The survivor Arnold Daghani published his memoirs in 1960 in German translation, accusing companies like Dohrmann and others to have assisted SS, SD and auxiliary troops in the deliberate killing of slave workers.

[...] The result is that [...] in proportion it harbours at least in its permanent administrative staff, possibly more ardent Nazis than a regular formation of the Party.