Final answer:
The establishment of speakeasies in the 1920s was an unintended consequence of Prohibition, the federal government's ban on alcohol.
Step-by-step explanation:
The establishment of speakeasies in the 1920s was an unintended consequence of the federal government action known as Prohibition. Prohibition was the nationwide ban on the production, sale, and transportation of alcoholic beverages. Since the demand for alcohol remained high, speakeasies, which were secret bars or clubs that operated illegally, emerged as a way for people to continue obtaining and consuming alcohol.
Learn more about Prohibition and the emergence of speakeasies