A termination that is unfair is not necessarily illegal.
Employers can usually fire employees for any reason.
However, there are exceptions to the at will rule. You have the right to see your personnel file. An employer must allow the employee to inspect the file within a reasonable amount of time after the employee asks to see it. It is also important to know that you can add your own documents to your personnel file, which may be a good idea if you disagree with some of the information in the file. Different laws provide similar rights to most public employees.