21st Amendment (Repeal of Prohibition)
Senate Joint Resolution 211, a proposed amendment to the United States Constitution, was passed on February 21, 1933. This resolution was sent to the states for ratification that same day. The 21st Amendment, ratified on December 5, 1933, is unique for two reasons. It is the only amendment to repeal another amendment (the 18th, which legalized Prohibition). Secondly, it was the only amendment to be ratified by state conventions assembled specifically to vote on it, rather than by state legislatures.
National Archives, General Records of the United States Government