The Holocaust
In his book Mein Kampf, Hitler declared his anti-Semitism beliefs. He also blamed them for the Wall Street Crash of 1929 a few years after his book was written. When he became Chancellor of Germany, he set up Dachau which became the first concentration camp. However, it was the Nuremberg Laws of 1935 that really started to dehumanize Jews with them being prohibited from any form of transport other than walking to forcing them to wear a Star of David badge that allowed people to identify them as Jews. Kristallnacht saw the killings of as many as 91 Jews killed. It wasn't until World War 2 started was when Jews were put into ghettos before being shipped out on trains to concentration camps like Auschwitz where they would be killed was when the Holocaust really kicked into gear. These were liberated when the Allied Powers took control of Nazi occupied European countries.