Relatively little is known about how late nineteenth-century associations worked to get their policy goals adopted by state governments. We study this question here, considering the Woman’s Christian Temperance Union (WCTU) and three policies it supported: scientific temperance instruction, increasing the age of consent, and prohibiting tobacco sales to minors. Overall, WCTU-supported legislation was more likely to succeed in states with unified Republican state legislatures, aided by neighboring state adoptions (scientific temperance) and greater WCTU membership (increasing age of consent and prohibiting tobacco sales to minors). These findings are supported by historical evidence, which reveals how WCTU leadership targeted particular states when lobbying for scientific temperance instruction laws and utilized its broad membership base to pressure state legislatures on the other two issues. In total, these results show how one late nineteenth-century membership group was able to facilitate the successful spread of its policies throughout the nation.