Prohibition was enabled by the 18th Amendment to the Constitution and enforced by the Volstead Act, which outlawed the manufacture, sale and transport of alcohol. The temperance movement that pushed for prohibition saw alcohol as the root cause of many of society's ills and expected the abolition of spirituous beverages to cure many of the country's problems. Prohibition lasted from 1920 to 1933, when it was reversed by the 21st Amendment. The law had many effects, many of them negative and a few that could be characterized as positive.

Economics

Part of the impetus for prohibition was the expectation that consumers would shift from the purchase of liquor to the purchase of other goods and services. The theory was that once the populace could no longer spend money on alcohol, it would focus its spending on other, more desirable needs and wants. Instead, the law had largely negative economic effects. There was no increase in general spending and in fact, the amount spent on entertainment and social activity dropped dramatically. Some restaurants were forced to close their doors, for example, because without liquor sales they could no longer make a go of it. Tax revenues were hit hard as the revenue once obtained from liquor taxes was eliminated. The state of New York, for example, saw tax revenue fall about 75 percent overall, forcing Albany to scramble for new sources of revenue.

Loopholes and Hypocrisy

The implementation of prohibition left many loopholes and back doors for those who wished to circumvent the system and continue distributing and imbibing alcohol. A clause in the law allowed physicians and pharmacists to provide liquor to patients as "medicinal" treatment, a situation that was ripe for abuse. Vintners increased their acreage and sold grape juice in packages with which consumers made wine at home. In New York City alone there were thousands of "speakeasies," illegal bars and nightclubs. The mass disrespect for the law bred corruption, from street cops who protected gin joints to judges and prosecutors who wound up in the pay of mobsters.

Crime

A natural result of outlawing a popular commodity is that criminals will take advantage of the situation, supplying it to the public at a premium. Prohibition encouraged all sorts of illegal activity -- from running alcohol into the States from Canada or across the water from the Bahamas to manufacturing moonshine in thousands of backwoods stills. While organized crime existed before Prohibition, it is generally acknowledged that Prohibition was a boon to the Mob, providing millions and millions of dollars in illicit profits. Wood alcohol and other cheap booze often proved toxic, causing blindness, paralysis and death for many unfortunate drinkers.

Lasting Positives

Some see positive effects of Prohibition. Dr. Jack S. Blocker, Jr. argued in the American Journal of Public Health that Prohibition's "flattening effect" on America's per-capita consumption of alcohol continued long after Prohibition ended. Others point to salubrious effects like a 66 percent decline in cases of cirrhosis of the liver among men as well as a 50 percent drop in arrests for public drunkenness.

Positive Heritage

Women might argue that the beginnings of their inclusion into the wider sphere of American social life began in Prohibition, thanks to speakeasies. Prior to Prohibition, saloons and bars had been male-only environs; with the era of the gin joints, though, the doors opened and women like men frequented speakeasies. Many commentators at the time decried this phenomenon as an affront to the idea that a woman's rightful place was at home, but from the 21st century perspective it looks more like women asserting their independence. Fans of stock-car racing can thank Prohibition for NASCAR, which got its start in the South, where moonshiners souped up their cars to out-run pursuing lawmen on the region's back roads.