How do you know if your boss is breaking the law by retaliating towards you?

very disrespectful to me in front of all my employees. Several employees were upset at her behavior. When I reported this to my boss he protected her and got upset at me. I then shortly there after received the worse evaluation in my career. He has harassed/retaliated towards me since then. I even reported to him and HR that employees transferring one area to another are not being treated fairly. A few did not get to transfer their benefits and others did. Employees began to complain so as the manager I'm require to report concerns. There has been no resolution nor follow up with any of the employees. I now believe they are looking to replace me are force me to quit. There are other issues as well and for the last several months I've been documenting incidents comments and or saving emails!