Pierre de Marigny de Mandeville, NSDAR Patriot #A205030, was born in New Orleans in 1740, the son of Antoine de Marigny de Mandeville and Francois de l'Isle. He married Jeanne Marie d'Estrehan. He was made Colonel of Militia and put in command of the new Spanish town of Galvezton, near Baton Rouge. When the demonstrations of the West against Spain threatened Baton Rouge, he was called upon to organize the militia.

He built a colossal Marigny fortune reputed to be seven million dollars at his death. To concessions obtained from France by his father Antoine, he added large concessions granted to him by Spain, and profiting by opportunities, Pierre invested in real estate, buying large plantations which made him not only the greatest landowner of New Orleans, but also its richest citizen. Pierre de Marigny de Mandeville also purchased land on the opposite shore of Lake Pontchartrain from New Orleans in what is now Mandeville. He died in 1800 and was buried in St. Louis Cathedral, New Orleans, Louisiana.

The town of Mandeville is known as the oldest inhabited locality in St. Tammany Parish. It was first settled in 1739 by pioneers who crossed the lake and moored up Bayou Castine. Further development came with Pierre's son, Bernard de Marigny de Mandeville.

It was said in 1902, that there was not a more beautiful place than Mandeville in all of the state of Louisiana. After all this time, Mandeville is still beautiful. It has a rich history, environment, and resources, and the residents will say that there is no place more pleasing to live.

--From the Pierre de Mandeville Chapter DAR Web Site

Find-A-Grave contributor CGH suggests the following from the "Archdiocese of New Orleans Sacramental Records, Volume 7, 1800-1803": "DE MARIGNY Pedro (Phelipe MARIGNY DE MANDEVILLE and Francisca DELISLE), Chevalier of the Royal and Military Order of St. Louis, militia colonel of this plaza, widower of Juana Maria DESTREHAN, cir. 50 yr., i. May 15, 1800, in the first section of the aisle of [the chapel of] our seraphic father, St. Francis, in this cathedral (SLC, F4, 89)"