I think that the best answer is the geographic location: many other countries (Sweden for example) have tried being neutral at different times but did not manage to: but the fact that the US has only two boundaries, and that both other countries also have a history of fighting from independence from a European power, makes it possible that unless US decideds to get involved in international politics, it can be "left alone".
Answer:
Germans murdered millions of Jews in Holocaust
They were discriminated and hatred called anti semitism of their religion
First, Missouri would be admitted to the union as a slave state, but would be balanced by the admission of Maine, a free state, that had long wanted to be separated from Massachusetts. Second, slavery was to be excluded from all new states in the Louisiana Purchase north of the southern boundary of Missouri.