Im not sure if you still need help but heres the answer. The holocaust happened because Hitler and the National Socialist (Nazi) party of Germany believed that the Jews held too much power in German politics (which I would like to note, they objectively did) and therefore should be removed from Europe. Hitler and the National Socialists believed that other non-aryans such as slavs and blacks do not belong in Germany and should also be removed. Basically Hitler believed that Germany should be for Germans only. Ironically, Israel a jewish country, preaches the same message but for themselves (Israel for Israelis) and most Israelis believe that they should remove non-Israelis from Israel so that they can be an ethnically pure country. Reasonable estimates put the holocaust death toll for jews at about 2.5 million, most dying of malnutrition or typhus (which was a disease that no one knew how to stop at the time).
Because Adolf Hitler preached that Jews, Gays, Blacks, etc were horrible. He made them seem like they are the devil himself. He rose to power and he willingly made concentration camps were Jews, Blacks, and Gays were forced to work or be killed for no reason. Then he and his wife shot themselves not because he realized what they have done was wrong but because they knew us Americans were coming to kill him.
