With very few exceptions, employers are not required to provide any sort of job verification or reference. If you identify the exact nature of the work and the state involved, it may be possible to determine if the person's past job falls into one of those exceptions, but on the whole it seems unlikely.

Perhaps there is another way to verify employment dates that will be satisfactory to the new employer -- such as confirmation of employment from a former supervisor or even a co-worker or co-workers who are willing to attest to the employee's work history and dates of employment.