At the end of World War I, the Treaty of Versailles separated West Prussia from the rest of Germany to make the Free City of Danzig and Polish Corridor, so Poland would have access to the ocean instead of being landlocked. Some people also wanted to break Prussia into smaller states, but this did not happen. Prussia became the "Prussian Free State" "(Freistaat Preußen)," the largest state in the Weimar Republic. The Prussian Free State made up more than 60% of all the land in the Weimar Republic. The Prussian Free State contained the industrial Ruhr area the city of Berlin, so many people with left-leaning political ideas lived there. The Social Democrats and the Catholic Centre had power for most of the 1920s. 