Religious identity denial facilitated treating slaves as property. [causal]
Eliminating the religious identities of slaves was central to the process of bifurcating black from Muslim identity during the antebellum era. Although Africans thrust into the American slave market hailed from a diverse range of tribal, ethnic, and religious backgrounds, their heterogeneity had no relevance to the law's conversion of them into property. Legal recognition of the religious identities of Africans would amount to a concession to their humanity and undermine the project of converting them into subhuman beings whom it was ethically permissible to enslave.
Khaled A. Beydoun, American Islamophobia_ Unde…, loc. 171