4/18/16 In addition to bootleggers, alcohol could be made legally during prohibition for religious or medicinal purposes.
Here’s what Ken Burns has to say:
One of the legal exceptions to the Prohibition law was that pharmacists were allowed to dispense whiskey by prescription for any number of ailments, ranging from anxiety to influenza. Bootleggers quickly discovered that running a pharmacy was a perfect front for their trade. As a result, the number of registered pharmacists in New York State tripled during the Prohibition era.
Because Americans were also allowed to obtain wine for religious purposes, enrollments rose at churches and synagogues, and cities saw a large increase in the number of self-professed rabbis who could obtain wine for their congregations.
I looked this up after seeing a collection of legal prohibition liquor bottles on Antiques Roadshow.