La Nouvelle-Orléans (New Orleans) was founded May 7, 1718, by the French Mississippi Company, under the direction of Jean-Baptiste Le Moyne de Bienville, on land inhabited by the Chitimacha. It was named for Philippe d'Orléans, Duke of Orléans, who was Regent of France at the time. His title came from the French city of Orléans. The French colony was ceded to the Spanish Empire in the Treaty of Paris (1763). During the American Revolutionary War, New Orleans was an important port to smuggle aid to the rebels, transporting military equipment and supplies up the Mississippi River. Bernardo de Gálvez y Madrid, Count of Gálvez launched the southern campaign against the British from the city in 1779. New Orleans remained under Spanish control until 1801, when it reverted to French control. Nearly all of the surviving 18th century architecture of the Vieux Carré (French Quarter) dates from this Spanish period. (The most notable exception being the Old Ursuline Convent.) Napoleon sold the territory to the United States in the Louisiana Purchase in 1803. Thereafter, the city grew rapidly with influxes of Americans, French, Creoles, Irish, Germans and Africans. Major commodity crops of sugar and cotton were cultivated with slave labor on large plantations outside the city.
You can read more at http://en.wikipedia.org/wiki/New_Orleans