For those interested, the marriage certificate has been found.
While the law forcing couples to wait 2 days between the license and the marriage had significantly reduced the number of couples going to Maryland to get married, some people still ran away to get married there.
The 2 days waiting period put Maryland on par with Delaware, NJ and Pennsylvania however Maryland gained popularity when there was no waiting period, and kept some of this popularity after the waiting period had been put in place.
It is possible that couples had a fantasy about eloping and wanted to go to Elkton or elsewhere in Maryland, even if they knew they'd have to spend 2 days there (or maybe they did not know, but they had seen it in a movie and when they were there, they simply waited 2 days as required). I believe the railway services made it convenient to go there from New York. From talking to an historian I learned these trains were called the "Honey Moon Express".
In my case, it could have been a combination of:
- A necessity to get married outside of NY (because the groom had been
married before and it was forbidden to remarry in NY).
- The convenience of going away from NYC so that the family who disapproved the union had a lower chance to know about
the marriage intentions (and possibly come across the marriage
license if they were published in the local newspaper -to be
verified-) and try to prevent it. No blood test required either.
- The popularity of Maryland making it the obvious destination to solve the above 2 challenges. The daughter of the bride seems to recall her mother telling her that they were at the train station and she was divided between serving in the military or getting married instead. The groom would have said "come with me" and they hoped on a train to Maryland.
Bear in mind that there are different counties in Maryland and not everyone got married in Elkton. There is also a difference between Baltimore city and Baltimore county and if the record you're looking for is not found at one office it could be at the other one (this was my case).
Finally, if you really have no idea where the act took place, you can start a search in every states of the east coast, starting from the most likely location, and look for the years you think it may have happened. That's how I initially ruled out a number of states. It is a very long process but there is a lot on the internet, and sometimes all you need is name.
http://cecilhistory.org/ is a useful website. But the old postcards, essays, podcasts and articles about eloping to Maryland are many.