In California, most employees are "at-will" employees.  This means that your employer can fire you at any time for any reason or no reason at all, other than certain types of discrimination, such as racial, gender, etc.  It sounds like you and your boss simply had a personality conflict and he didn't want you around any more.  Unless you have a signed work contract, you are an at-will employee and you are out of luck, I'm afraid.  Time to look for a new job.