In 1980, over one hundred twenty thousand Cubans fled to the United States as part of the Mariel Boatlift. Though the vast majority were admitted to the United States, several thousand found themselves in long-term detention due to criminal records or mental illness. The federal penitentiary in Atlanta served as the primary detention site throughout much of the 1980s. In November 1987, the Cuban detainees led an uprising and took control of the prison for eleven days after learning that the United States had reached an agreement with Cuba to repatriate Cuban detainees. This dissertation examines the expansion of immigrant detention during the 1980s through the lens of Mariel Cubans at the Atlanta Federal Penitentiary. I explore the local debates that took place and the ways in which many Atlanta residents attempted to aid the Cuban detainees. I trace the long arc of resistance in Atlanta, examining how Cuban detainees and their allies in Atlanta protested detention policies and prison conditions before and after the 1987 uprising. This work sheds light on how local debates and inside-outside resistance can shape national immigration policies.