The saga began with ratification of the 18th Amendment, which banned the manufacture, sale, or transportation of alcoholic beverages in the United States.- and noticed that the 18th Amendment did not ban the consumption of alcohol. This was confirmed at the Wikipedia page: "Prohibition was instituted with ratification of the Eighteenth Amendment to the United States Constitution on January 16, 1919, which prohibited the "...manufacture, sale, or transportation of intoxicating liquors within, the importation thereof into, or the exportation thereof from the United States..."
Now I'm wondering why, in so many movies, scenes depicting raids on speakeasys show the patrons fleeing the establishment? (I think The Cotton Club had a scene like that). If patrons were not doing anything illegal in consuming alcohol, why do they jump out windows and escape through back doors to the alley?