It's a long drive, but I recommend Marconi Beach:
http://www.nps.gov/caco/planyo.....-beach.htmhttp://www.yelp.com/biz/marconi-beach-wellfleetI've been to a lot of beautiful beaches, but I will never forget the spectacular beauty of Marconi Beach and the Cape Cod area in general. Marconi Beach literally took my breath away. I loved the drive up the Cape to get there too...so pretty and beautiful.
I looked it up - it it would be a full two day's drive there (and back) so maybe not the most practical option. Ack!
Just for the record, I also looked up Naples, FLA ...but it's also a good distance from Chicago. If there's some way to get to Naples - then this would be at the top of my recommendations for a romantic beach holiday. I think Naples is one of the nicest spots in Florida - well worth the trip, imo. If you happened to choose Naples, FLA, you could whip up to Orlando in your car mid-week for a blast of fun at DisneyWorld and see the other tacky (but fun) sights in Orlando. Go back down to Naples and carry on with your romantic vacation. The nearest airport to Naples is Fort Meyers, which is only about 20-30 minutes drive to Naples, if you were to consider flying instead of driving.
Here's hoping others can chime in with some fab options that are a little bit closer. I wish I knew of beautiful honeymoon destinations within a reasonble driving distance of Chicago - but alas, I don't have much to offer since I haven't been to Chicago yet, and don't know what's nearby.
Looking foward to hearing what you choose for your well-deserved and long-overdue honeymoon.