The Holocaust was the state-sponsored, systematic persecution and annihilation, of European Jewry by Nazi Germany and its collaborators, between 1933 and 1945. (Definition according to the USHMM)
The Widespread of Concentration Camps
Concentration Camps were camps where people where held under cruel conditions without a legal arrest. After Hitler became the chancellor of Germany in 1933, the first concentration camps were made. As more people started being viewed as the "political opponents" and "social deviants" that were to be held in the camps, more camps had to be established. The concentration camps increasingly grew in numbers, especially right after WWII started and there were more prisoners of war and threats. The camps started being set up in places where the prisoners could be put to work on something useful such as mining or construction.
The United States Involvement in the Holocaust
The United States didn't make rescuing Jews and those targeted by the Nazis a main priority during WWII. We also did not give it the correct publicity; we instead lived the stories down or barely included them at all. It was hard for immigrants and escapees to get a visa to get into the U.S. Even though it was tough to immigrate into the States, almost half of the people immigrating into the U.S. were Jewish.
Convincing the Country
Between 1919 to 1932 Germany was in an unstable state of government, this is when the Nazi Party started to rise to power. They showed themselves as a group that was trying to salvage and return order to German society by uniting the "Aryan" Germans. By using propaganda to convince people that they were trying to make a peace-loving country, they got people to fight in the war for Germany. They displayed that they were the innocent victims that were forced to fight back, when really they were dominating other countries.