It was through Propaganda and Silencing of people lead to people denying the fact that the holocaust was happening, and only rumors about concentration camps where among ally troops until they finally liberated them.
The holocaust was the mass genocide of jewish people by the nazi party so the so called "superior" german race could rule over Europe. Nazis beliwved jews were the rats that were investing Europe.
The Black Death wiped out much of the population on the European landscape.
Hope this helps!
Farmers (those were wealthy farmers which the Soviet regime didn’t like)
William Penn founded it
and it was a land grant bc his farther owed money to the king