Answer:
Because it was the year where the first government framework was written, specifically in Massachusetts
Step-by-step explanation:
According to Britannica: "Mayflower Compact, document signed on the English ship Mayflower on November 21 [November 11, Old Style], 1620, prior to its landing at Plymouth, Massachusetts. It was the first framework of government written and enacted in the territory that is now the United States of America."
And in addition to that, the Battle of The White Mountain happened in the 8th of November of the same year