South Dakota v. Dole

Two facts set the Twenty-first Amendment: it was the only amendment passed to repeal a previous amendment, and it was the only one ratified (albeit indirectly) by the electorate through a vote for delegates.

The Eighteenth Amendment (1919) prohibited the manufacture, sale, and distribution of alcohol. The Volstead Act (1919) authorized the creation of a Prohibition Bureau to enforce the law. In spite of this and the Supreme Court's tacit approval for broadened government police powers, as evidenced by decisions such as Olmstead v. United States (1928), the new law-enforcement mechanism proved ineffective.

The opposition to Prohibition spread to the Democratic Party, which in its 1932 presidential platform called for repeal of the Eighteenth Amendment. The Senate passed an amendment resolution, and on 20 February 1933, the House endorsed it as well. The new amendment, in addition to repealing the Eighteenth, contained a prohibition against transporting alcohol in violation of state law.

During the months between April and November, citizens of 38 states voted for delegates, and with 73 percent of the votes in favor of repeal, the actual ratification conventions were mere formalities.