[3] In 1842 he accepted an invitation from his relative, Bishop Guy Ignatius Chabrat, to join the Diocese of Louisville, Kentucky.

[4] Following his arrival in the United States, Lavialle continued his studies at the diocesan seminary and was ordained to the priesthood on February 2, 1844.

[4] He was appointed to succeed Antoine Blanc as Archbishop of New Orleans, Louisiana, in 1860, but he refused the honor.

[5] During his short tenure, he conducted diocesan visitations, invited the Dominican Fathers and founded a convent for them, erected four churches in the episcopal see of Louisville alone.

[4] Exhausted from his labors, Lavialle retired to St. Joseph's Infirmary and next to Nazareth, near Bardstown, where he later died at age 46.