Can I sue my former employer for discharging me for false reasons?

I was discharged from my employer for false reasons. The reasons that my employer gave me for discharging me was performance and conduct issues. I worked at the company right at 12 years. As long as I worked for the company, I've never had any performance or conduct issues. I've never been written up or verbally warned about anything. All of my performance reviews are excellent. I receive my raises every year. Actually, I just received a merit raise in January 2018.

My HR file is clean and clear of any write-ups or warnings of any kind. When I made an attempt to ask questions in the meeting regarding my termination, I was told by the HR Generalist that they were not there to answer any questions that day. The HR Generalist also informed me that my Manager was also giving me the option to resign. I stated to the HR Generalist that I didn't have a reason to resign. Then the HR Generalist stated to me then it will have to be the discharge.