In the late 1600s, French trappers and traders began settling in what is now New Orleans, along a Native American trade route between the Mississippi River and Lake Pontchartrain via Bayou St. John. In 1718 the city was officially founded as "Nouvelle-Orléans" by Jean-Baptiste Le Moyne de Bienville, Governor of the French colony of Louisiana, with the intent to build it into a provincial capital city. The early French city grew within the grid of what is now the French Quarter. Louisiana was transfered to Spanish rule in the 1760s, but much of the population retained French language and culture. After briefly returning to French rule, Louisiana was purchased by the United States in 1803. At first the new "American" settlers mostly built their homes and shops upriver from the older French parts of the city, across wide "Canal Street" (named for a planned canal that was never built). Canal Street was the dividing line between the Anglophone and Francophone sections; the street's wide median became a popular meeting place called "the neutral ground" -- and "neutral ground" became the common phrase for the median of any street, still in use in the New Orleans dialect today.

A British attempt to seize the city in 1815 was repelled downriver from the city in Chalmette by local forces led by Andrew Jackson, whose equestrian statue can be seen in the square named after him in the center of the old Quarter.

Early New Orleans was already a rich melting pot of peoples and cultures. French Spanish African and Anglos were joined by immigrants from Ireland, Germany, and the Caribbean. While a center of the slave trade before the American Civil War, New Orleans also had the USA's largest population of free people of color. The city grew rapidly as a major trade center on the mighty Mississippi River. In the American Civil War of the 1860s, New Orleans fell to the Union early in the conflict without battle within the city, sparing the city's rich historic architecture from the destruction suffered by much of the American South.

At the start of the 20th century, the then largely neglected old French Quarter started gaining new appreciation among artists and bohemians for its architecture and ambiance. Around the same time, a new musical style developed in the city; the music developed and swept around the world under the name of "jazz".

Although far from the big battlefronts, New Orleans is proud of its contributions to the Allied victory over Fascism in World War II, especially the development and construction of landing craft such as "Higgins Boats" which made rapid landing masses of troops on hostile beaches possible. This legacy is why America's National World War II Museum is located in the city.