My great-grandfather Vincenzo negotiated Prohibition by fermenting two barrels of wine a year. It was perfectly legal, he insisted. Vincenzo was lucky to be a New Yorker. In her fine history of Prohibition, “The War on Alcohol,” Lisa McGirr, a professor of history at Harvard, shows us that a poor Italian in Illinois or a black man in Virginia might very well have been jailed, shot or sentenced to a chain gang.

Chain gangs are a far cry from Prohibition’s lore, which imagines puritans winning a ban on liquor that America flatly rejected. Magazines gleefully published “bartender’s guides,” directing the thirsty to the nearest whiskey. The law spawned crime, shootouts and a kind of gangster romance embodied by Jay Gatsby. Worse, drinking became hip. Young people ­sported flasks and haunted speakeasies. Eventually, inevitably, the whole mess ­collapsed.

In reality, outlawing alcohol had many supporters and inspired more fervor than any reform except abolishing slavery. An extraordinary coalition conquered liquor. Women fought for protection from abusive husbands. Southern leaders grasped for more control over black lives. Progressive reformers attacked the workers’ saloons where machine politicians swapped favors for votes. Western populists hoped to tame the urban Gomorrahs. Methodists funded the Anti-Saloon League, which grew so formidable it inspired a new term of political art — the interest group. With congressional ratification of the Prohibition amendment in 1920, alcoholism plummeted; drinking levels did not rebound to pre-Prohibition levels for half a century. The “noble experiment,” as McGirr shows, reflected a deep heartland yearning to protect American health and morals from the rising tide of foreigners, cities, social problems and jazz.

McGirr makes two major contributions to the historical record. First, she vividly shows how enforcers targeted immigrant and black communities. During the 1910s, immigration reached its all-time high — 41 percent of New Yorkers had been born abroad — and, suddenly, there were more people in the cities than the countryside. McGirr documents Prohibition’s nativist spasm by zooming in on Herrin, Ill., where labor violence transformed into a war on Italian drinkers. Incredibly, national ­officials deputized the local Ku Klux Klan, which raided homes, rounded up violators and shot resisters. In the South, blacks faced impossible fines or hard time. McGirr has less to say about the racial tangle of segregation, lynching and Prohibition — still the untold story of the era.