The Twenty-first Amendment to the United States Constitution lifted the country-wide alcohol prohibition introduced in the United States in 1920 with the eighteenth amendment. It was passed by Congress on February 20, 1933, and on December 5, 1933, enough state parliaments had ratified it. It has been ratified as the only additional amendment not by the parliaments of the individual states, but by specially elected assemblies. This procedure was chosen because the influence of anti-alcohol activists on many parliamentarians and party leadership in the individual states was still very strong.