Why did prohibition ended in the United States

The Night prohibition ended. By the 1930's, it was clear that Prohibition had become a public policy failure. The 18th Amendment to the US Constitution had done little to curb the sale, production and consumption of intoxicating liquors. and while organized crime flourished, tax revenues withered. (I hope this answers your question)

which time period is this? or is this story fictional, i'm going to need more info to answer this question