Abstract: Politics Distilled: Prohibitionists, Moral Reform, and the American Party System, 1869-1933 investigates the political culture that sustained the longest-living minority party in American history: the Prohibition Party. It explores how Prohibitionists—led by temperance advocates, women, and former abolitionists—harnessed their moral aspirations to politics and partisan strategies. The Prohibition Party was a social and political movement in which diverse groups of Americans challenged the party system's limitations as a conduit for ethical and democratic governance. Party members' debates, both internal and with other civic associations, emphasized the role of religion in politics, the significance of third party challenges, and the process of translating vision into policy. This dissertation explores the Prohibition Party's transforming agenda and ideals against the backdrop of two critical developments in the history of American political institutions: the ascendancy of special interest organizations and ballot reforms that effectively excluded minor party tickets. It examines the character of radical political transformations during the late nineteenth and early twentieth centuries, and elucidates how Americans experienced these changes as both constraints upon and opportunities for greater participation in governance.