Anti-Semitism had been around in Europe for hundreds of years. Pogroms, attacks on Jewish communities, took place long before the Nazis took power.
The Nazis opened Dachau concentration camp near Munich, on March 22, 1933, to be followed by Buchenwald near Weimar in central Germany, Sachsenhausen near Berlin in northern Germany, and Ravensbrück for women. At first intellectuals were targeted for deportation, and then “undesirables” like the retarded or criminally insane.
The Nuremburg Laws of 1935 prevented a diverse group of people from holding government jobs, teaching in schools and universities, or owning or operating businesses. This group included Jews, homosexuals, communists, socialists, evangelical Christians, Gypsies, and those critical of the Nazis. The laws defined who was “racially” pure.
Germans got used to the disappearance of their neighbors. Many Germans supported the deportations as a necessary part of reclaiming German national pride. Thousands were sent to concentration camps between 1933 and 1939. Jews were deported after Krystallnacht on November 9, 1938. At first these deportations did not mean automatic death. The camps were holding areas for political prisoners.
After the fall of Poland in September 1939, SS Chief of the Reich Central Security Office (RSHA) Reinhardt Heydrich questioned his subordinates about the future of Polish Jews. Already some of the SS had murdered Polish Jews by gunfire. Heydrich decreed on September 21, 1939, that Jews would be rounded up and forced into urban ghettoes, the largest of which were the ghettoes of Warsaw and Lodz.
The Ghettoes were infested with vermin and disease, and the Germans kept cramming more and more Jews into them. Some were taken to slave labor camps, while the rest were put on half rations. Synagogues were wrecked, and Jews were forced to dance around the burning Torahs.
Also in 1941 the Germans set up the Vernichtungslager (Death Camps.) Unlike the slave labor camps, where prisoners worked until they died, the Death Camps sole purpose was to dispose of human life.
The largest camp was in Auschwitz, Poland. Unlike any other camp because it was both a labor and a death camp, Auschwitz was set up on January 25, 1940. By 1943, 6,000 people were dying each day. By 1944 the camp's death apparatus was expanded to 12,000 a day. Other Death Camps included Treblinka, Maidenek, Sobibor, Belsec, and Chelmno. The camps were all in Poland, which had a large Jewish population and well-built rail system.