Married or not, how do we know?

[trazzie]

My finace and are are currently living in Wisconsin, but in Aug. we are flying out to be married in Las Vegas, NV. One of the requirements to apply for a marriage license is to know the date of your divorce if previously married. My finance had a very short marriage years ago in Missouri, it was less then 6 months and he can not recall the date of the marriage nor the date of the divorce. As I was searching for this information I started to suspect that his divorce was never finalized. He was told by his then wife that it was finished, but he does not recall ever signing any legal documents. My questions are 1. Is there a way we can indeed find out if his divorce was ever finalized without knowing the dates? 2. How would he go about getting a divorce when he is no longer living in the state and he has no knowledge of her whereabouts. Thank you!