The freedom of assembly has been at the heart of some of the most important social movements in American history: Antebellum abolitionism, women's suffrage in the nineteenth and twentieth centuries, the labor movement in the Progressive era and the New Deal, and the Civil Rights movement. But in the past thirty years, assembly has become little more than an historical footnote in American political theory and law. At least part of the reason for its loss is attributable to the judicially recognized right of association that emerged in the middle of the twentieth century. After tracing the histories of assembly and association and the political, jurisprudential, and theoretical factors that shaped the modern right of association, I argue that the shift from assembly to association undermines the principle of group autonomy for at least three reasons: (1) associations acceptable to a national consensus replace dissenting assemblies; (2) the public assembly becomes the private and depoliticized association; and (3) the assembly as form of expression becomes the association as means of expression. I offer a legal and theoretical roadmap for a return to assembly that can reclaim some of the autonomy for groups that has been sacrificed by the freedom of association. I also suggest how some religious groups might discover greater theoretical and theological resources in assembly.