Just one little thought about if the USA and the Confederation of Southern America split California. I cannot see Southern California developing the way it did. By the 1900's LA with its booming population was putting pressure on its own water supply thus needing to build an aqueduct to the Sierra Nevada with by the looks of the map only a small part of it lie in Confederation claims. Without the aqueduct Southern California would be dry and probably would not be as populous or economically as powerful as it could be. This provided I am correct in that the Sierra Nevada is the only source of water that can be found.