""By the blessing of heaven, directing the valor of the troops under my command, one of the most brilliant victories in the annals of war was obtained."
--General Andrew Jackson to the Ursuline Nuns
New Orleans Archbishop Gregory Aymond will celebrate the annual Mass of the Solemnity of Our Lady of Prompt Succor at 4 p.m. today at The National Shrine. 
In 1727, Mere Marie Tranchepain and eleven other Ursulines traveled from Rouen to New Orleans. Within a few months, they had boarding students, the beginning of what is now the "Oldest Continuously-Operating School for Women in the United States".
In 1803, they wrote to Ursulines in France, asking for more nuns to join them in Louisiana. In March, 1809, Mother St. Michel Gensoul wrote to Pope Pius VII, asking if she could accept the invitation. She prayed before a statue of the Virgin Mary, asking for prompt succor -- quick help. She had the pope's permission within six weeks. She took the statue of Our Lady of Prompt Succor and several postulants with her to New Orleans.
During the night of January 7-8, 1815, the Ursulines and many of the citizens of New Orleans spent the night before the statue, praying that General Jackson and his small army of frontiersmen, pirates, Choctaws, free blacks, militia, dragoons, etc. would be victorious over the British forces.
As Bishop DuBourg said Mass in the morning, "a courier ran into the chapel  to inform all those present that the British had been defeated".
Since that time, a Mass of thanksgiving has been celebrated every year on the anniversary of the Battle of New Orleans.
(A feminist history of this congregation, so important in American Catholic history, may be read online: Masterless Mistresses: The New Orleans Ursulines and the Development of a New World Society, 1727-1834,  by Emily Clark, published by the University of North Carolina Press, 2007.)