Here’s an interesting discussion.

"We sometimes here [sic] that there were Creoles in Mobile who served as soldiers for the Confederacy. It appears there were some, and it is thought they were largely a fire company of Creoles who were upset that they were not allowed to serve as the other fire companies were. In the Deep South of that day, there were a class of Creoles that were recognized as free forever because of the treaties with France and Spain that brought much of that area into the US.

"However, here is the attitude the admittance of these men into the Confederate Army as expressed by the Secretary of War in November of 1863:"

The Mobile Creoles

http://civilwartalk.com/threads/the-mobile-creoles.6400/