German authorities under National Socialism established a variety of detention facilities to confine those whom they defined as political, ideological, or racial opponents of the regime. In time their extensive camp system came to include concentration camps, where persons were incarcerated without observation of the standard norms applying to arrest and custody; labor camps; prisoner-of-war camps; transit camps; and camps which served as killing centers, often called extermination camps or death camps Concentration Camp System: In Depth
Not something I know a lot about but stumbled upon this CIA file ,its online (for now) at https://www.cia.gov/library/readingroom/docs/GERMAN CONCENTRATION CAMPS_0001.pdf SHAEF Evaluation and Dissemination document. Kyle
The best book to read about the concentration camp system and its history is KL by Nikolaus Wachsmann (ISBN: 978-0349118666). From the moment the Nazi's took power they set up such camps in many places, some no more than a basement or a barge, and included Esterwegen in the Emsland Camps system and Columbia Haus located on the edge of Templehof airfield.
I have the publication, it is a first class insight to the method used by the NSDAP to eliminate the opposition from when Hitler took power from January 1933....genocide came later. The judicial system failed those who died within the KLs, a repetitive entry on a death certificate was recorded as "heart failure" Those who had the moral courage to represent victims of the regime found themselves running the risk of being arrested and incarcerated in a KL themselves. Research will throw up a number of these people of moral courage who made a stand for democracy and paid for it with their lives. From the hell of the KLs, the SS became "business entrepreneurs" arising from the workings of quarries such at the notorious quarry at Mauthausen and brickyards. Any transaction that slave labour could be exploited for the means of creating wealth for the SS was undertaken.
