On the southeast corner of Conti and Claiborne Streets in the city of Mobile stands the Greek revival Creole dwelling that served as the residence of the Bishop of Mobile from 1834 through the first decade of the twentieth century. Called the Portier House after the first Bishop of the diocese, the date of its construction has not yet been fully determined. It seems certain that the structure has been standing for some time before purchase by its first ecclesiastical owner.

Michael Portier was born in Montbrison, France on September 7, 1795, and after volunteering as a missionary for the service in Louisiana was ordained in St. Louis on September 29, 1818. He worked for many years in New Orleans and was notably successful in the field of education before he was named head of the newly erected Vicariate-Apostolic of Alabama and the Floridas in 1825. Having been consecrated at St. Louis in November, 1826, Portier arrived at Mobile in December that same year. He spent another year working and surveying conditions before leaving for Europe where he secured substantial help from both France and Rome.

His vicariate having been raised to the rank of a diocese in 1829, the missionary prelate returned to his city of Mobile to found Spring Hill College, establish Visitation Convent and Academy, and bring greater order and growth to the works of religion over which he had been given charge. One author, writing while the memory of those days yet lived, described the churchman's dwelling place in theses words: "Bishop Portier's Episcopal palace was a small frame house, twenty-five feet by fifteen, divided into two rooms, in which he resided for five years." Such a residence was hardly big enough for Portier and the two priests who were attached to the Cathedral Parish and it is likely that a house on the de Angelis property where the Visitation was eventually to be located was also used as a residence until the sisters arrived. It was after that that the bishop purchased the house described above. Portier reported the transaction to his Roman superiors noting that the structure contained ten rooms and cost $7,000—money well spent, he thought, to give the "Bishop and clergy an honorable residence and a handy one without losing sight of evangelical simplicity."