In case after case, prosecutors, judges and juries therefore still struggle to come up with a definition of slavery, looking for some set of criteria or indicia that will enable them to discern whether the phenomenon they are observing constitutes enslavement. In this definitional effort, contemporary jurists may imagine that in the past, surely the question was simpler: someone either was or was not a slave. However, the existence of a set of laws declaring that persons could be owned as property did not, even in the nineteenth century, answer by itself the question of whether a given person was a slave. How was such status to be determined in everyday social life, and how was it determined if disputed in a court of law? The complexity of the question became explicit in what might otherwise appear to be an arcane detail of the law of slavery: the claim to “freedom by prescription,” under which a person who had in good faith “lived as free” could argue that the absence of exercise of ownership for a specified term of years extinguished a prior owner’s title to that person as property, and entitled that person to liberty. The present article tracks the concept of freedom by prescription through its intricate relationship with the law of status and the law of property. Although nineteenth century Louisiana provides the examples, the implications extend beyond that unusual mixed civil law/common law jurisdiction. To anticipate: As courts sought to discern the presence or absence of slave status, they were caught between formal doctrinal arguments that aimed to block claims of freedom by prescription, and competing vernacular understandings of what it meant to “be” free. Moreover, in a set of moves that anticipate modern deliberations about conditions “analogous to slavery,” both sides adduced evidence of social relations on the ground and argued about what they implied. Therefore, although status was generally conceptualized as a legal fact that needed simply to be determined, it actually looked much more like a set of practices that needed to be interpreted.
Scott, Rebecca J. "Social Facts, Legal Fictions, and the Attribution of Slave Status: The Puzzle of Prescription." L. & Hist. Rev. 35, no. 1 (2017): 1-22.