Scientific Temperance Instruction was the most successful grassroots education program in American history, championed by an army of housewives in the Woman's Christian Temperance Union under the leadership of Mary Hanchett Hunt. As Hunt and her forces took their message across the country, they were opposed by many educators and other professionals who believed that ordinary citizens had no business interfering with educational matters. STI sparked heated conflict between expert and popular authority in the debate over alcohol education, but it was eventually mandated as part of public school curricula in all states. The real issue surrounding STI, argues Jonathan Zimmerman, was not alcohol but the struggle to reconcile democracy and expertise. In this first book-length study of the crusade for STI, he shows Mary Hunt to be a wily and manipulative politician as he examines how citizens and experts used knowledge selectively to advance their own agendas.