“On November 18, 1918, prior to ratification of the Eighteenth Amendment, the U.S. Congress passed the temporary Wartime Prohibition Act, which banned the sale of alcoholic beverages having an alcohol content of greater than 2.75%. (This act, which had been intended to save grain for the war effort, was passed after the armistice ending World War I was signed on November 11, 1918.) The Wartime Prohibition Act took effect June 30, 1919, with July 1, 1919, becoming known as the "Thirsty-First".
On October 28, 1919, Congress passed the Volstead Act, the popular name for the National Prohibition Act, over President Woodrow Wilson's veto. The act established the legal definition of intoxicating liquors as well as penalties for producing them. Although the Volstead Act prohibited the sale of alcohol, the federal government lacked resources to enforce it. By 1925, in New York City alone, there were anywhere from 30,000 to 100,000 speakeasy clubs.”
“Prohibition in the United States – Wikipedia”