During the Jim Crow era, Black activists appealed to a diverse population of migrating Black Americans by making them viscerally feel that the threat of anti-Black violence continued to afflict them as a group and to undergird blackness itself. To this end, they organized public gatherings, mostly comprised of Black people, that fostered fears of looming physical harm. Samuel Galen Ng illuminates this Black consciousness as it emanated from feelings of collective endangerment. The dissemination and intensification of such feelings became a pivotal way of solidifying a national Black consciousness on the eve of the Civil Rights Movement. Ng examines how performances of Black endangerment performed political work that provided Black people with important means of political organizing and insurgency. As Ng shows, the grief and mourning that took place at the performances provided public spaces for individuals and communities to observe specific losses capable of impacting Americans across the country. Ambitious and interdisciplinary, Assemblies of Sorrow explores an overlooked facet of Black organizing and protest and traces how activists shaped fear and grief into political action.