The story
Coined independently on a few occasions between the 1940s and 60s, notably by KATC by adding an a to the end of Acadian. By surface analysis, Acadia + -ana.
Etymology from Wiktionary, CC BY-SA 4.0.
Acadiana
Today it means: An official region of the U.S. state of Louisiana comprised of 22 parishes (equivalent to counties in other U.S. states), which is the historical heartland of the state's francophone population; notably inhabited by Cajuns and Louisiana Creoles. Full definition →