Immigration scholars have framed the nation-state as inhospitable to an abolitionist approach to sanctuary. Retheorising and reconceptualising the merging of abolition and sanctuary policies, practices, and sites within the context of democratic nation-building, this chapter develops an alternative understanding. The chapter unveils how, in the United States, ‘abolition sanctuary’ guided the development of Northern personal liberty laws that once protected runaway slaves from being returned to slavery under federal fugitive slave law (1787–1860). Abolitionists leveraged American federalism to create robust sanctuaries under state and local governing institutions and policies. This was critical to their success in protecting runaway slaves and the longer-term project of reimagining the American nation-state. Today, abolition sanctuary is a similarly powerful framework for fighting against unjust immigration enforcement regimes at all levels of government while simultaneously developing a vision for immigrant justice to inform democratic nation-building.