Is this wrongful termination?

[fmwmbmbm4]

I worked for a financial institution. I deposited a 3rd party check into my personal account. They called it altered because I wrote my name in the pay to line (the check was given to me blank). After their investigation, including them contacting the maker of the check, my explanation was concurred with. I was then terminated because I had had a previous warning. Although, I have never seen documentation of a verbal or written warning.

Thoughts? Suggestions for recourse?

Thanks,