Ever since the suffrage movement in the early twentieth century, governments around the world have enacted far-reaching reforms that have brought women into political life -- as voters, officials, and politicians. This fascinating book explores the logic of these historic changes, focusing on three advancements: women's suffrage, government bureaus mandated to address women's issues, and, more recently, gender quotas for national legislatures. In detailed empirical chapters, Towns untangles the complex ways in which states have adopted new practices. They have done so in "waves" of legislation among "clusters" of states. Women's suffrage, for example, first broke through in small western U.S. states and then spread to the rest of North America and western Europe; this was followed by movements in eastern Europe and Latin America, which then moved into Africa and Asia after states in those regions gained national independence. These patterns, Towns argues, reveal much about how states compare, rank, and compete with one another and how sudden shifts in notions of legitimacy can trigger transnational social movements.