Many came from peoples of the same region of West Africa, thus concentrating their culture.
In the post-Civil War environment, Anglo-Americans increased the pressure for Anglicization, and in 1921, English was for a time made the sole language of instruction in Louisiana schools before a policy of multilingualism was revived in 1974.
In between the Tertiary rocks of the north, and the relatively new sediments along the coast, is a vast belt known as the Pleistocene Terraces.
Their age and distribution can be largely related to the rise and fall of sea levels during past ice ages.
Louisiana slowly developed, over millions of years, from water into land, and from north to south.