The 18th Amendment to the Constitution, ratified in December 1919, effective 1920, was repealed by the 21st Amendment in 1933, ending Prohibition.
It’s important to understand that the 18th Amendment to the United States Constitution
did not directly make it illegal to drink alcohol. Instead, it prohibited manufacturing, selling, or transporting intoxicating liquors within the United States and its territories.
Some states didn’t do it, and at least one stopped enforcement. It also allowed consumption for religious purposes. Without it, there would have been a conflict with the First Amendment.
There were other loopholes in Prohibition. While you couldn’t legally buy or produce
new alcohol, you were allowed to drink alcohol that you already possessed before the 18th Amendment’s enforcement date OR legally obtained before Prohibition started. Medicinal prescriptions, like sacramental alcohol above, were also exempt.
So, possession for personal use was technically legal. Still, the avenues for legally obtaining new supplies were limited, making drinking alcohol criminal unless one had pre-existing stocks or used one of the few legal loopholes. How would anyone honestly 
know? A lot of people store whiskey and wine for years or claim to.
Trying to enforce these laws led to widespread non-compliance and the rise of speakeasies, bootlegging, and organized crime. My grandparents were in the bar business forever, and I remember stories about bathtub gin. Here’s a tidbit: it wasn’t produced in a bathtub but used its tap.
So, go out tonight to your favorite speakeasy and enjoy a glass of medicinal bathtub gin in celebration, but keep an eye out for Eliot Ness.
