California wasn’t the property of the federal government. It was a free state free to choose.
Any overtures from the CSA were not to take California (or any other territory) as booty, but to allow the inhabitants the authority to choose for themselves.
Figured out the issue of West Virginia yet?
Hmmm, let's see. What do they call it when hostile foreign agents come into the boundaries of a legitimate nation and attempt to destabilize it?