The Holocaust was a Significant event during World War II

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…by gas. When the war ended, millions of Jews, Slavs, Gypsies, homosexuals, Jehovah's Witnesses, Communists, and others targeted by the Nazis had died in the Holocaust. The Holocaust was driven by the Nazi ideology of racial superiority and inferiority. Combined with Hitler's quest for lebensraum, "living space," and his goals of world domination and with World War II as a cover, the Nazi regime was able to carry out the greatest crime in human history.