New Orleans has been a Catholic city since its French founding in 1718, and its diocese, established in 1793 and raised to an archdiocese in 1850, ranks among the oldest in the Mississippi valley, giving the city a Creole Catholic identity distinct from the Protestant South surrounding it on every side. Rural Cajun parishes to the southwest, settled by French speaking Acadian exiles beginning in the 1760s, kept a related but separate Catholic identity built around parish life conducted in French well into the twentieth century.
New Orleans also became the historic center of Louisiana Voodoo, a tradition enslaved West Africans built by blending Vodun cosmology and ritual practice with the Catholic saints already present in the city around them, so that a given spirit could be honored through the image and feast day of a saint understood to share its character. Scholarship on the African American conjuring tradition treats this blending not as disguise alone but as a genuine theological synthesis, one that let practitioners keep core elements of West African religious practice alive under a colonial Catholic order that would not have tolerated it presented openly. Marie Laveau, the nineteenth century practitioner popularly remembered as Voodoo Queen of New Orleans, is the tradition's best known figure, and her tomb in Saint Louis Cemetery Number One still draws visitors who leave offerings at it much as an earlier generation might have brought them to her directly. The two traditions, Catholic and Voodoo, did not simply coexist in New Orleans, they shaped each other's practice in ways still visible in the city's religious life today.