With a monarchy it is one person who makes all the rules instead of a government like we have where the powers are split up so no one branch has more power than another, where a monarchy has all the power, kinda like a king.
The colonies got their independence from Great Britain. The slaves who were promised freedom for fighting in the war (on both sides) I would assume we're granted freedom.
Germany joined in September 1939
I think it went south to north. that is what I have heard