The temperance movement was largely a function of culture rather than any religious doctrine.

At the time, the United States was going through fundamental convulsions of what it meant to be an American, and the temperance movement was one of the expressions of that white Protestant insecurity. At the risk of violating the 20-year rule, it's quite comparable to the modern insecurity surrounding immigration, right down to the fevered conspiracy theories.

The vast majority of settlers in America before 1840 were Protestants descended from the British Isles, with a substantial minority of Germans. Immigration first picked up in the 1840s as Irish fleeing the potato famine and Germans fleeing the revolutions of 1848 began to settle in the United States. The Irish were all Catholic, as were many of the Germans-- which all played into traditional Protestant fears of a Papist plot against America.. This manifested itself in the antebellum years as the virulently anti-immigrant Know-Nothing Party.

Between 1870 and 1920, this nativism only got worse as waves of penniless Jews, Poles, Czechs and Italians flooded the cities. Conditions for new immigrants were horrendous in places like Five Points, Manhattan. If you think New York City is crowded now, imagine what it was like in 1910-- it was totally normal to have 16 people living in 900 square feet. Immigrants did work that was dangerous, repetitive, and unskilled. Disease was rampant. The social safety net was nonexistent.

One of the few amusements that these new immigrants could afford was liquor. And boy, did they drink a lot of it. Because a saloon wasn't just a place to drink. It was also a place for community, and a place where the immigrants' new political power could be organized. Many urban political bosses were saloon-keepers, including Boss Tweed in New York and P. J. Kennedy of Boston. (P.J. Kennedy's grandson John was elected President of the United States in 1960.)

The drunkenness of the era disgusted Protestants, both as a social problem, and because the saloon represented a way for Catholics and Jews to exercise their political strength. At the time, Protestants commonly believed that Catholics were part of an international conspiracy to turn America over to the Pope. Similar conspiracy theories were trotted out against Jews.

To the reformers of the era, it followed naturally that the way to reassert white, Protestant political control and to bring about moral reform was to eliminate booze. It's a position with little theological support, but that didn't matter-- after all, these were ethnic questions, not theological ones. In other words, the churches followed the politics, not the other way around.

sources:

• Okrent, Last Call.

• Pegram, One Hundred Percent American.

I've been reading Drink: A Cultural History of Alcohol by Iain Gately, and he points out that Christian priests railing against alcoholism was an issue even back in the Middle Ages, despite Christian monasteries being a major source of wine. The problem was that many people went to pubs instead of to church, which not only cut down on the size of the congregation, but also on the money the church would earn when they sold alcohol on certain feast days.

On a moral level, it was already clear that drinking lead to many of the venal sins. "Gluttony introduced its victims to its fellow deadly sins sloth, lechery and pride. Drinkers spent all day in bed, were careless of how they appeared and grew fat through inactivity. Those who could rouse themselves to any degree were all lust and boast, but mostly the latter for pride was construed to be the "devil's wine." [ebook, location 1551]

So there was a threat of prohibition in the Church for a long time before the temperance movement became a thing. According to Daniel Okrent's Last Call, the Temperance Movement was gained strength from the participation of women, who were often victims of alcoholic husbands, who might abuse them, neglect them and spend money that could have gone to the household.