This dissertation reinterprets the long civil rights movement by centering Black women NAACP activists in Arkansas and western Tennessee between 1935 and 1970 as architects of the system’s infrastructure. I argue that the durability of civil rights gains depended not primarily on the iconic moments preserved in national memory, but on sustained institutional political labor, membership cultivation, financial stabilization, youth mentorship, coalition-building, and strategic care, performed largely by Black women within local branches. Drawing on primary sources and insights from Black feminist thought, I reimagine the organizational ecosystems that undergirded mid-twentieth-century civil rights activism in both rural and urban southern communities. I demonstrate that long before and long after nationally recognized moments connected to the civil rights movement, Black women designed, maintained, and defended the institutional structures that made civil rights victories both possible and durable. Bringing civil rights historiography into sustained conversation with Black feminist theory, particularly its insights on care, relational labor, and institutional life, this study advances the concepts of institutional political labor to explain how democratic participation becomes durable over time. I recast the civil rights movement not as a sequence of event-driven triumphs, but as a cumulative process of organizational construction carried out under conditions of racial violence, political repression, and ideological transition. By recognizing the Black women in my study as institutional architects, this dissertation reorients civil rights history toward maintenance, durability, and disciplined collective care as foundational to the movement's endurance.