The passage of the 18th amendment represents nearly a century of agitation for temperance laws. There were a number of factors that affected the ideas of the Americans of the time, and so eventually when enough support was gained for temperance the 18th amendment was finally passed. Here are the events that led to prohibition and the effect that prohibition had on America, especially in the big cities.
The temperance movement really began in 1866 when an English Physician named Sir Benjamin Ward-Richardson disproved the myth that alcohol keeps the body warm. This discovery, combined with a number of other discoveries concerning alcohol helped to stir up some support for the temperance movement.
Another factor affecting the minds of Americans was the large scale pressure put on the Presidents and Congresses of the time by the United States Brewers Association, or the USBA. These brewers represented more than 78% of the beer brewed in America making them a very powerful political influence.
Suspicious Americans began to see a pro-alcohol conspiracy in Washington, especially after well publicized scandals such as the St. Louis Whiskey Ring. People began more and more to see alcohol producing companies as amoral corporations out to make a dishonest buck. Saloons more than anything dissuaded people from liquor. In the 1890's there was one saloon for every 300 people, an amazing statistic. Cities were the worst, especially in the industrial north. For example there were more saloons in Chicago than in the entire south. Eventually the anti-saloon league was created, an alliance for the complete shutdown of every saloon in the country.
Accidents resulting from drunkenness were both common in the 1900s and well publicized. Often these accident involved heavy machinery and resulted in the death of fellow factory workers. Eventually companies began to prohibit alcohol...