The killing of six million Jews, political enemies, Roma and other groups is known as the Holocaust. Adolph Hitler and his Nazi party enacted a program of persecution and conquest in Germany that lasted 12 years. Millions died and many starved in a conflagration that swept much of Europe and even drew the United States into the Second World War. Hitler believed that Jews and non-whites were inferior and a threat to the hegemony of the Aryan, or German people. Gradually Hitler enacted various laws and ordinances that took away the rights of Jews and non-whites. Eventually he had Jews placed in ghettos, which were isolated areas where Jews were supposed to live, and there were often curfews in place to limit their movements.
Before Hitler came to power in 1933, there were approximately nine million Jews in Europe. Most lived in countries such as Germany, Poland, France and the USSR. Along with political dissidents and minorities, Hitler felt strongly about those who were disabled or mentally ill. He felt they were also inferior and targeted them for death and sterilization in a euthanasia program.
The Nazi party formed concentration camps to hold political enemies and minorities. Some of the most famous of these camps were Dachau, Treblinka and Buchenwald. Conditions were atrocious and many died of starvation, disease, exposure and worse. People within these camps were used as forced labor on projects such as building roads, and worked in factories and mines. For those too weak to work, such as the elderly, children and disabled, something far worse was done to them. Some people were killed in gas chambers, rooms constructed to allow poisonous gas to filter in and kill those inside. Others were shot, or experimented on.
On May 7, 1945, the Nazis surrendered to the Allied army, ending the Holocaust and World War II. Very few of the prisoners in the concentration camps survived, Many died from conditions, lack of medical treatment or the death marches Nazis made prisoners walk in, to prevent their freeing by the Allies.