Gilbert Antoine de St . Maxent Gilbert Antoine de St . Maxent ( 1724 – August 8 , 1794 ) was a merchant and military officer who played a major role in development of the Louisiana Territory during its era as New France and New Spain . Maxent was born in Longwy , Meurthe - et - Moselle , in Lorraine , France . In 1747 he immigrated to New Orleans , Louisiana . He enlisted in the military and in 1749 married the wealthy Elizabeth La Roche and used the dowry to open a building on Conti Street to supply fur traders . In 1753 he was promoted to colonel and commandant of the Louisiana Regiment by Governor Louis de Billouart Kerlerec . He was to distinguish himself in battles defending Louisiana against incursions by the British and Chickasaws in the French and Indian War . Founding of St . Louis . In 1755 Kerlerec gave Maxent exclusive rights to deal with Native Americans west of the Mississippi River . Maxent ' s most ambitious effort was the formation of Maxent , Laclede and Company in which he gave 25 percent ownership to Pierre Laclède . In 1763 LaClede selected a site on a bluff above the west side Mississippi just south of the confluences for a settlement that was to be called St . Louis , Missouri . According to legend , work on clearing the site began on Valentine ' s Day 1764 . St . Louis was founded before news arrived that in the Treaty of Paris ( 1763 ) that ended the French and Indian War Spain would take over the Louisiana possessions of France on the west of the Mississippi River and that the British were to take over the east side of the river ( officially administering what was to be Native American territories ) . After news arrived French settlers on the east side of the river moved to the west side at St . Louis . Rebellion of 1768 . Maxent whose fortune was tied to France was to have his loyalties severely tested in the transition from French to Spanish control . Maxent was one of the first Frenchmen to pledge his allegiance to the new Spanish governor Antonio de Ulloa and Ulloa was named godfather of one of Maxent ' s daughters . Maxent entered into contracts to supply Spanish frigates . When the Creole and German settlers around New Orleans resisted Spanish rule in the Rebellion of 1768 they imprisoned Maxent at his plantantion from October 25 – 29 , 1768 releasing him after Ulloa was forced out of the city to return to Spain . In January 1769 Maxent was to thwart efforts by the plotters to enlist Native Americans to fight any attempt by the Spanish to reclaim New Orleans . In May 1769 the partnership with Laclede was dissolved with Laclede buying the St . Louis facilities for 80 , 000 livres with the first payment due in June 1771 . In August 1769 Alejandro O ' Reilly restored Spanish authority in New Orleans putting down the rebellion and executing five ringleaders and imprisoning five others . O ' Relly abolished the Superior Council which had governed Louisiana replacing it with the Spanish Cabildo and replaced the French laws with Spanish code . O ' Reilly gave Maxent a new patent for the fur business for the firm St . Maxent and Ranson . The firm which rivaled LaClede ' s was to contribute to Laclede ' s declining fortunes in St . Louis . Maxent ' s daughter was to marry to the next Spanish governor Luis de Unzaga . During this period he was to believed to have been the richest man in the entire territory and built a series of lavish homes . In the Great New Orleans Fire ( 1788 ) which destroyed most of New Orleans , Maxent was officially commended by the Spanish for opening his home to many refugees from the fire and for selling supplies to the Spanish at the same price as was before the fire . American Revolution . During the American Revolutionary War Spain sided with the French and United States against the British and Maxent was placed in charge of the militia ( but not Spanish forces ) which were to see action in the Gulf Coast campaign s including the Capture of Fort Bute , Battle of Baton Rouge ( 1779 ) ( which included battles at Fort New Richmond and Fort Panmure near Natchez , Louisiana , Battle of Mobile ( 1781 ) , and ultimately the Battle of Pensacola ( 1781 ) . For his actions , he was named Commandant of the Militia of Louisiana , Lt . Governor of the Providence of Louisiana and West Florida , Captain - General of the new Bureau of Indian Affairs of Louisiana and West Florida . In 1782 , he traveled to Spain to get concessions from Carlos III including doing permission to import slaves with paying duty . As part of the negotiation , he agreed not to export specie ( gold bars ) . While returning to Louisiana in 1782 , his two ships and crew were captured by the British and sent to Kingston , Jamaica where Maxent was held under house arrest and his men in prison . Maxent and his men got lenient treatment through bribes . The revolutionary war ended with the Treaty of Paris ( 1783 ) and Maxent ' s fortunes quickly soured when his enemies were at peace . One of the British benefactors was arrested in Havana , Maxent was implicated in a smuggling specie ( gold ) and the Spanish revoked all his titles and his property was embargoed . Adding to his woes his New Orleans wharehouse was destroyed in the Great New Orleans Fire ( 1788 ) and in 1789 he was ordered arrested again by Spanish governor Esteban Rodríguez Miró . Maxent was to eventually clear himself of the charges but the process was to tie him up for the rest of life . The next Spanish governor Francisco Luis Héctor de Carondelet called him back to military duty to help build Fort San Felipe . Carondelet recommended that he be promoted to Brigadier General but he died in 1794 .