Today's modern state of Louisiana in the United States is only a small proportion of the land territory that was sold by Napoleon Bonaparte in 1803 called the Louisiana Purchase.
(map from Wikipedia, may contain errors)
Sadly, it seems that only the state of Louisiana has maintained or tried to maintain its French heritage.
There was a great article in Monocle magazine (June 2010 edition) about the revival of French language and teaching in schools in Louisiana, with the assistance of the French government.
- France-Louisiana Agreement
- Council for the Development of French in Louisiana/
Conseil pour le Développement du Français en Louisiane