From Encyclopedia of Camps and Ghettos, 1933–1945
The Mittelbau (Central Construction) concentration camp was the last main camp created by the SS-WVHA, and the only one not named after a specific place.
Although the camp officially came into being on October 28, 1944, its origins stretched back to the founding of a subcamp of Buchenwald, codenamed Dora, on August 28, 1943. On that date, the SS trucked 107 Buchenwald prisoners to tunnels in the southern Harz mountains, near the small central German city of Nordhausen. These unlucky individuals were to pave the way for the thousands more tasked with converting a central petroleum reserve for the Reich into a secret factory for the A-4 ballistic missile, later christened the Vengeance Weapon (Vergeltunswaffe-) 2 or V-2.
Dora was not the first instance where prisoners were sent out of a main camp to be used in the armaments industry, rather than exploited in SS camp industries. However, it proved to be a highly influential model for the many new and often grotesquely unrealistic underground projects that the Nazi leadership ordered in response to the Anglo-American strategic bombing offensive. The Nordhausen region got a number of such projects. Mittelbau emerged as the camp system that embodied in its purest form the final phase of the SS concentration camps: that of large-scale exploitation of prisoners for work in the war economy.
In the end, Mittelbau proved true to its name. In a system of up to 40 subcamps attached to Dora, most of the prisoners worked in construction of underground and aboveground facilities under murderous conditions. Other than the V-2, and later V-1, missiles that came out of the underground plant, very few weapons were actually produced. Thus the emphasis on Mittelbau as a weapons-production complex in much of the historiography is certainly exaggerated, as the German scholar Jens-Christian Wagner has pointed out.
In fact, out of the approximately 40,000 prisoners in Mittelbau in March 1945 (of whom approximately 16,000 were in the main camp), less than 6,000 at the main camp and those at a few small subcamps were actually employed in production. The majority were construction workers and miners, supplemented by thousands of ill and exhausted survivors of the evacuations of Auschwitz and Gross-Rosen since the beginning of the year.
Michael J. Neufeld, from Encyclopedia of Camps and Ghettos, 1933–1945 (Jack, Joseph and Morton Mandel Center for Advanced Holocaust Studies, United States Holocaust Memorial Museum).