The multicultural composition of the Lower Mississippi Valley remained strong even after the cessation of Louisiana to Spain in 1763, the retrocession to France in 1800, and the Louisiana Purchase in 1803 by Thomas Jefferson ,effectively making the state of Louisiana of both representative of the diversity of the United States and unique for its distinctive colonial past.
The French made Louisiana a port city shipping timber,minerals, agricultural products and perhaps most notably high quality furs from the Mississippi Valley and the interior of the still unexplored continent , transported downriver to New Orleans for quick delivery to Europe.So USA got its political identity as a nation which could export lot of things to Europe.