Since your husbands employment was in Georgia, Georgia law will control the issue. I am a TN attorney and will discuss TN law as it may be similar to GA law but you might want to repost this question and list GA as your location so you will be more likely to get a GA attorney to answer.
In TN an employee is NOT entitled to unpaid vacation time upon termination unless the company has a policy otherwise. TN is also a right to work state and a company would generally be able to lay your husband off in favor of a less experienced employee if they chose.
Again GA law may be different and hopefully you can get a GA attorney to answer by reporting with GA as your location.
This answer does not constitute legal advice nor form an attorney client relationship. I am not your lawyer. If you have a legal issue in Tennessee you may contact me for a free consult.