Beer in the United States
On January 16, 1919, the Eighteenth Amendment to the United States Constitution was enacted into law, creating the Prohibition era, wherein the production, sale and transportation of alcoholic beverages was made illegal. All legal American brewing came to a halt when prohibition was imposed, though the earlier temperance movement had already reduced the number of breweries significantly. Only a few breweries, mainly the largest, were able to stay in business by manufacturing near beer, malt syrup, or other non-alcohol grain products, in addition to soft drinks such as colas and root beers. Production and shipping of alcohol was largely confined to illegal operations that could deliver compact distilled beverages—smuggled rum and domestic moonshine—more efficiently and reliably than bulkier products such as beer.
Cocktails for Two
The song seems to refer to the ending of Prohibition in the United States. Mentioned discreetly in the song's introduction is that people could be "carefree and gay once again". The song was written in 1934, and the 21st Amendment, which ended Prohibition, was ratified in December of the previous year.