The 1830s saw a reconsideration of the institution of slavery across the South, in which the sense of slavery as an anomalous institution within a republican society gave way to the articulation of more aggressive claim of slavery as a positive good. As southern intellectuals and polemists shifted from apology for slavery to celebration of it, the sanctity of property rights both in slaves and more generally came to be interpreted as a measure of the Southern States’ success in balancing freedom and order. Alongside that shift, the importance of constitutions within the Southern imaginary grew. This chapter traces the constitutionalization of slavery that these developments gave rise to. In the first instance, slavery as an issue was “constitutionalized” through an overt association of slavery with constitutional rights. At a second level, constitutionalization proceeded in a greater attachment to extant constitutions and a call for their preservation as central objects of political life. This chapter shows how these two developments, placed together, resulted in a conflux of slavery and constitution that made defense of each imperative to the other.