The Eighteenth Amendment to the US Constitution banned the manufacture, sale, or transportation of intoxicating liquors in the United States. No importation. No exportation. One interesting historical fact is that when the Amendment was voted on, most people thought that “intoxicating liquors” only meant distilled alcohol. That it would not cover things like beer and wine which were not distilled. It was a great surprise to many when the Volstead Act specifically included them as types of “intoxicating liquors.” This would lead to the creation of the various “Near Beers” that had low enough alcohol contents to slip under the Volstead Act, as well as companies selling ingredients that could be used to make “intoxicating liquors” with clear instructions on what NOT to do with them. It would be wrong to allow people to accidentally break the law due to lack of knowledge, doncha know? Coincidentally, one of the primary fuels used for most automobiles at the time was various distilled alcohols of some type, since any farmer could find something to distill on their farm, and alcohol actually burns more cleanly than oil-based gasoline. Gas stations as we know them now were largely limited to the big cities, until this amendment made distilling alcohol-based fuel illegal.