This is probably a lightning rod topic (or at least it's underpinning supposition is), but I'm gonna ignore my better judgement and throw it out there anyway. So a short to medium length Anglo-American War following a cocked up Trent Affair has been discussed in depth on this site before. If we assume the high range of harm by British forces blockading and marauding through California, is Britain able to hold whatever is left of California afterwards? How long would it take for the Empire-born population to outnumber the American-born population? How long would it take to become self-governing and become a 'normal' dominion? When would it gain control of its own immigration policy? I ask because in OTL Canada was in a position to halt Indian immigration and Australia wouldn't have a bar of Japanese immigration whether Japan was a British ally or not. I wonder if California would just have to shut up and accept whoever Britain decided could go there. What would happen to Hawaii in such a situation?