Is it right for a company to terminate you after 24 yearssaying that your job performance is not up to par without any type of warning?

Personally, I would say it is not right. Unfortunately that does not necessarily mean it is illegal. If your state has at will employment, then that means either party, you or the company, are free to terminate the employment arrangement at any time, unless there is a contract which specifically states an employment term. Check to make sure you are not under any kind of contract. If there is a union at your company they may be able to help you. Sometimes the union steward will help you even if you are not personally a member of the union.