Here's the breakdown:
* Acadia was a French colony in what is now Nova Scotia, Canada.
* Acadians were the French colonists who lived there.
* In the 18th century, many Acadians were expelled from their homes by the British.
* They eventually migrated south to Louisiana, where they settled and became known as Cajuns.
The word "Acadiens" evolved into "Cadiens" and then into "Cajuns" as a result of pronunciation shifts and the influence of English.