Why is Prussia not a country?

With the end of the Hohenzollern monarchy in Germany following World War I, Prussia became part of the Weimar Republic as a free state in 1919. It effectively lost this status in 1932 following a decree of Reich Chancellor Franz von Papen (the Preu├čenschlag); Prussia as a state was abolished de facto by the Nazis in 1934 and de jure by the Allies of World War II in 1947.