"Although the Constitution has been formally amended 27 times, the Twenty-First Amendment (ratified in 1933) is the only one that repeals a previous amendment, namely, the Eighteenth Amendment (ratified in 1919), which prohibited “the manufacture, sale, or transportation of intoxicating liquors.” In addition, it is the only amendment which was ratified, not by the legislatures of the states, but by state ratifying conventions, as called for by the Amendment’s third section. The Constitution, in Article V, allows for ratification by either method." - ConstitutionCenter.org