The First Concentration Camp

The Defense Department will house up to 20,000 unaccompanied migrant children on military bases in coming months, a Pentagon official said Thursday. ~ Washington Post, June 21, 2018

Dachau

The first concentration camp in Nazi Germany was at Dachau, founded in 1933 just weeks after Hitler became Chancellor. Its purpose was to house political prisoners, liberals and communists, for "reeducation." Its location in Bavaria was chosen because it was where Nazi support was strongest and the local population was unlikely to protest. It evolved, in time, into a forced labor death camp.

The first concentration camp specifically for murdering those the Nazis deemed subhuman, like Jews, was Auschwitz–Birkenau. Auschwitz was opened in 1940 in occupied Poland to hold Polish political prisoners. The Birkenau extermination camp annex was built in 1941. Fully operational, it could kill and cremate 20,000 people in a day.