Even in the Deep South, Louisiana is just different. A uniquely French history and culture, very Catholic instead of fundamentalist Christian, Parishes instead of Counties. But New Orleans is the outlier and not part of Acadiana. Historically part of French Louisiana, present-day Acadiana was inhabited by Attakapa Native Americans at the time of European encounter. After the expulsion of French-speaking Acadian refugees from Canada by the victorious British at the end of the Seven Years' War, many Acadians settled in this region. The Acadians intermarried with other settlers, forming what became known as Cajun culture.
In 1971, the Louisiana State Legislature officially recognized 22 Louisiana parishes and "other parishes of similar cultural environment" for their "strong French Acadian cultural aspects". It made "Heart of Acadiana" the official name of the region.