The histories I've read of the prohibition movement portray the people supporting it ridiculous for one reason or another. I've always wondered if they were in fact looking for a solution to a real problem (and decided on one that didn't work). How widespread was alcoholism in 19th century America and did it get any worse after the Civil War?
You might be interested in this answer I wrote on drinking in the United States during the 19th century.
Americans drank a lot (mostly hard cider and whiskey) in the early 19th century, to the point that visiting Europeans remarked on it. The estimates are that the average American drank 7 gallons (or 26.5 liters) of pure alcohol a year in the 1830s, which is above any country's current average intake per the WHO.
The Temperance Movement developed in reaction to this. Originally members of the movement advocated moderate drinking (usually abstaining from hard liquor and drinking wine and beer), but this evolved into advocating complete abstinence from drinking alcohol. Eventually the movement went further from advocating voluntary abstinence to pushing for prohibition laws. While national Prohibition lasted in the United States from 1919 to 1933, the first state to enact state-level prohibition was Maine in 1851, and the last state to repeal state-level prohibition was Mississippi in 1966. There are still counties and localities across the United States that have legal prohibition.
I should add to that answer and say that the temperance movement from its start in the 1830s with Lyman Beecher was associated with Christianity, especially evangelical Protestant Christianity (Catholicism to a degree in that Catholic groups supported abstinence but not legal prohibition). But the temperance movement was also connected to other reform movements, notably the women's suffrage movement, which advocated for Prohibition as a means to improve the physical and financial safety of women. The temperance movement was also associated with labor rights for much the same reason - the working class men who were considered susceptible to alcohol abuse leading to spousal abuse and poverty were also seen to be targeted by saloons conveniently located next to (and sometimes owned by) their places of employment. By 1900 there were some 215,000 legal salloons in the United States, and tens of thousands more unlicensed ones. Compared to that, there are about 72,000 licensed bars and nightclubs in the United States today, for a national population that is 4.5 times larger. As for drinking trends after the Civil War - total average alcohol consumed actually fell in the 1860s and 1870s, before rising again in the 1880s, 1890s, and especially the 1900s - there's a chart in a follow-up comment to my linked answer that has more details.
I got a great answer from /u/Bodark43 on a related question here.
