Final answer:
The Eighteenth Amendment, ratified in 1919, made it illegal to produce, distribute, and sell alcohol in the United States, which was enforced by the Volstead Act.
Step-by-step explanation:
The law that made it illegal to produce, distribute, and sell alcohol in the United States was the Eighteenth Amendment, ratified in 1919. More specifically, The Volstead Act, which was the piece of legislation that enforced the amendment, was passed later in 1919 over President Wilson's veto.
Although the primary intention was to curb alcohol consumption, the law had numerous unintended consequences, including the rise of bootlegging and speakeasies. The amendment did not outlaw the act of drinking alcohol itself, but effectively made it difficult to do so legally. This period, known as Prohibition, lasted until the Twenty-First Amendment repealed it in 1933.