I'm attempting to determine who might be the father of my great-grandfather Pierre (aka Peter Cousin aka Joseph Peter Cousins). His mother was Marie Eveline Xavier (b. 1824). He had several siblings. Two of his sisters (Rosa and Josephine) married into the Broyard family. I've seen a birth record for Josephine listing her father as Anatole Cousin. I've also seen several mentions online about Rosa's father being Anatole, but no actual records of that yet. At the time of the 1860 census, Octave Cousin (Anatole's brother, as far as I can determine) considered Eveline's residence in St Tammany to be his 'usual place of abode'. However, in 1870 he is living with Delphine Morgan and her children.

I'm not sure where to go from here. If I can prove the parentage of a few more of his siblings, I can probably make the leap that Anatole was also his father. The siblings had enough descendants that there should be at least a few relatives somewhere (here, maybe?) who would have that information. Alternately, does anyone know where in Louisiana I could locate birth or baptismal records which aren't available online?

I would appreciate any information that might help me figure this out.