Is this wrongful discharge

I worked as a certified fire inspector. The company I worked for started a new policy for our inspection reports we fill out. This new policy is illegal. I let the employer know it, and anonymously questioned the state Fire Marshal's office concerning the issue. The Fire Marshal's office confirmed that it was illegal. I have repeatedly told the employer that it was wrong but, was demanded to do it or lose my job. During my recent annual employee evaluation I was told I am doing a great job and would be getting a 3% raise. I make much less than the average in the field and less than any other employee with the same or less experience. I asked for a larger raise and was told NO and that maybe I should look elsewhere. I told the employer that I would have to at some time consider that option and that I would let him know. I left the office and the employer came after me and then stated how such a horrible employee I was and that I was fired. I beleive I was fired in retaliation for accusing the company of an illegal policy.