The 18th Amendment, which banned the manufacture, sale, and transportation of alcoholic beverages, was passed in 1920. In the previous decades, Progressive reformers had made the argument that alcoholism was the greatest cause of poverty, illness, premature death, criminality, and corruption. The temperance movement was spearheaded by Protestant women who viewed alcohol consumption as the largest contributing factor to the breakup of marriages and families. For many, banning alcohol was seen as addressing a public health issue.

But at its core, Prohibition was not simply about addressing a public health crisis: it was an anti-immigrant stance to try to control mainly Catholic immigrants. Many immigrants, especially those from Ireland and Germany, had different drinking habits from American-born Protestants. As these immigrants started their own breweries, formed their own lobby to protect their interests, and made sizable profits from selling beer, many Protestant women reformers joined forces with hate groups, such as the Ku Klux Klan, to push for Prohibition and to minimize immigrants’ impact on shaping American culture.