He was a student at the seminary in Lyon when recruited by Bishop Louis William Valentine Dubourg for the American mission.

He sailed from Bordeaux with Dubourg and about thirty companions on the French ship of war Caravane and landed after sixty-five days at Annapolis, Maryland on 4 September 1817.

Upon his recovery, Dubourg called Portier to New Orleans, where he established a collegiate school in the former Ursuline convent in the French Quarter.

At the time of his accession, Portier was the only clergyman in the vicariate and had practically three parishes with churches: Mobile, St. Augustine, and Pensacola.

St. Mary's College, Emmitsburg, Maryland, sent by Bishop England of Charleston, to take charge of the deserted church of St.

[3] Portier began his administration by riding through his vicariate, offering the Eucharist, preaching, and administering the Sacraments as he went.

Portier also consecrated John Stephen Bazin, another president of Spring Hill, and later the third Bishop of Vincennes, Indiana on October 24, 1847.

He brought the Brothers of the Sacred Heart from France about 1847, and the Daughters of Charity from Emmitsburg, Maryland, to manage orphan asylums for boys and girls, respectively.