The Catholic Church has had a presence in New Orleans since before the founding of the city by the French in 1718.
Missionaries served the French military outposts and worked among the native peoples.
The area was then under the jurisdiction of the Bishop of Quebec.
In 1721 Fr.
Francis-Xavier de Charlevoix, S.J., made a tour of New France from the Lakes to the Mississippi, and visiting New Orleans, he describes "a little village of about one hundred cabins dotted here and there, a large wooden warehouse in which I said Mass, a chapel in course of construction and two storehouses".

In 1722 the Capuchins were assigned ecclesiastical responsibility for the Lower Mississippi Valley, while the Jesuits maintained a mission, based in New Orleans, to serve the indigenous peoples.
The Jesuit vicar-general returned to France to recruit priests and also persuaded the Ursulines of Rouen to assume charge of a hospital and school.
The royal patent authorizing the Ursulines to found a convent in Louisiana was issued September 18, 1726.
Ten religious from various cities sailed from Hennebont on January 12, 1727, and reached New Orleans on August 6.
As the convent was not ready, the governor gave up his residence to them.
They opened a hospital for the care of the sick and a school for poor children.

New Orleans and the rest of Louisiana west of the Mississippi were surrendered to the Spanish in 1763.
From then until 1783 the East and West Florida were under British control, but as part of the Peace of Paris (1783) the two Florida colonies were regained from Great Britain.
Thus, the pioneer parishes of New Orleans and Louisiana were incorporated into the Diocese of Louisiana and the Two Floridas when it was erected on April 25, 1793.
The diocese originally encompassed the entire Louisiana Purchase, from the Gulf of Mexico to British North America, as well as the Florida peninsula and the Gulf Coast.

The date of its establishment makes it the second-oldest diocese in the present-day United States: the Diocese of Baltimore was established on November 6, 1789.
At the time of its establishment, the territory of the Diocese of Louisiana and the Two Floridas was part of the Archdiocese of San Cristobal de la Habana, based in Havana,  Cuba.

The diocese was divided into smaller dioceses several times, and many modern dioceses in the central United States were originally part of the Diocese of Louisiana.
As capital of the Louisiana, the city was sold to the United States in 1803.
The diocese was renamed the Diocese of New Orleans in 1826, and encompassed what is now Louisiana and Mississippi.
New Orleans was elevated to an archdiocese in 1850.
As the population of Louisiana grew, the Archdiocese of New Orleans was further subdivided into several additional dioceses.

In its long history, the archdiocese and the city of New Orleans have survived several major disasters, including several citywide fires, a British invasion, the American Civil War, multiple yellow fever epidemics, anti-immigration and anti-Catholicism, the New Orleans Hurricane of 1915, Segregation, Hurricane Betsy, and an occasional financial crisis, not to mention Hurricane Katrina.
Each time, the archdiocese rebuilt damaged churches and rendered assistance to the victims of every disaster.
More recently, the church has faced an increased demand for churches in the suburbs and a decline in attendance to inner-city parishes.
The church has also weathered changes within the Roman Catholic Church, such as the Second Vatican Council, and changing spiritual values throughout the rest of the United States.

The archdiocese sustained severe damage from Hurricane Katrina and Hurricane Rita.
Numerous churches and schools were flooded and battered by hurricane-force winds.
In the more heavily flooded neighborhoods, such as St. Bernard Parish, many parish structures were wiped out entirely.
The Catholic Church has had a presence in New Orleans since before the founding of the city by the French in 1718. Missionaries served the French military outposts and worked among the native peoples. The area was then under the jurisdiction of the Bishop of Quebec. In 1721 Fr. Francis-Xavier de Charlevoix, S.J., made a tour of New France from the Lakes to the Mississippi, and visiting New Orleans, he describes "a little village of about one hundred cabins dotted here and there, a large wooden warehouse in which I said Mass, a chapel in course of construction and two storehouses".
In 1722 the Capuchins were assigned ecclesiastical responsibility for the Lower Mississippi Valley, while the Jesuits maintained a mission, based in New Orleans, to serve the indigenous peoples. The Jesuit vicar-general returned to France to recruit priests and also persuaded the Ursulines of Rouen to assume charge of a hospital and school. The royal patent authorizing the Ursulines to found a convent in Louisiana was issued September 18, 1726. Ten religious from various cities sailed from Hennebont on January 12, 1727, and reached New Orleans on August 6. As the convent was not ready, the governor gave up his residence to them. They opened a hospital for the care of the sick and a school for poor children.
New Orleans and the rest of Louisiana west of the Mississippi were surrendered to the Spanish in 1763. From then until 1783 the East and West Florida were under British control, but as part of the Peace of Paris (1783) the two Florida colonies were regained from Great Britain. Thus, the pioneer parishes of New Orleans and Louisiana were incorporated into the Diocese of Louisiana and the Two Floridas when it was erected on April 25, 1793. The diocese originally encompassed the entire Louisiana Purchase, from the Gulf of Mexico to British North America, as well as the Florida peninsula and the Gulf Coast.
The date of its establishment makes it the second-oldest diocese in the present-day United States: the Diocese of Baltimore was established on November 6, 1789. At the time of its establishment, the territory of the Diocese of Louisiana and the Two Floridas was part of the Archdiocese of San Cristobal de la Habana, based in Havana,  Cuba.
The diocese was divided into smaller dioceses several times, and many modern dioceses in the central United States were originally part of the Diocese of Louisiana. As capital of the Louisiana, the city was sold to the United States in 1803. The diocese was renamed the Diocese of New Orleans in 1826, and encompassed what is now Louisiana and Mississippi. New Orleans was elevated to an archdiocese in 1850. As the population of Louisiana grew, the Archdiocese of New Orleans was further subdivided into several additional dioceses.
In its long history, the archdiocese and the city of New Orleans have survived several major disasters, including several citywide fires, a British invasion, the American Civil War, multiple yellow fever epidemics, anti-immigration and anti-Catholicism, the New Orleans Hurricane of 1915, Segregation, Hurricane Betsy, and an occasional financial crisis, not to mention Hurricane Katrina. Each time, the archdiocese rebuilt damaged churches and rendered assistance to the victims of every disaster. More recently, the church has faced an increased demand for churches in the suburbs and a decline in attendance to inner-city parishes. The church has also weathered changes within the Roman Catholic Church, such as the Second Vatican Council, and changing spiritual values throughout the rest of the United States.
The archdiocese sustained severe damage from Hurricane Katrina and Hurricane Rita. Numerous churches and schools were flooded and battered by hurricane-force winds. In the more heavily flooded neighborhoods, such as St. Bernard Parish, many parish structures were wiped out entirely.
Roman Catholic Archdiocese of New Orleans