A post overnight visit update........
The visit was a HUGE success. DS had a great time and learned a lot. He had exacly everything he needed with him, thanks to the kind folks who provided feedback on this forum.
For the benefit of any other parents facing this overnight visit, here is my two cents worth. Dress and grooming are extremely important in any "first impression" college situation, but probably even more so in this arena. I don't think it's necessary to go overboard, but my son wore crisply pressed khakis, dress shirt and tie. He brought a second similar outfit for the next day.
We were told by the admissions office that he should be sure to bring a towel and toiletry items and I imagine most people would expect that requirement.
But here is something to keep in mind when packing..... When calling to schedule the overnight visit, you may be asked what activities your child has an interest in - in our case, my son's application had already been submitted and when we called to schedule, the person in the office already knew what activities he was interested in from the application and just verified.
Keep those activites in mind when packing. I wasn't sure what to expect so we packed a pair of athletic shorts, T-shirt (I recommend that you are mindful of slogans and artwork on those T-shirts), socks and running shoes. On a last minute hunch, I threw a pair of swim trunks in the duffle bag* (I'll get back to the duffle bag in a second).
The academy seems to try and match up visitors with students who are already involved in the activity your child is looking at. I sort of expected that but in my son's case, he was interested in band, sailing and crew. I wasn't sure what combination of clothing would work for any or none of those possibilities but I figured a generic pair of shorts, T-shirt and running shoes was a good compromise.
It worked out perfectly as he changed into those clothes to go to practice with the offshore sailing team. He didn't have his boat shoes or sailing gloves, but he made out just fine. Luckily he had his sunglasses with him.
He said he got to sleep on a cot in the room with his host and roommates and then attended morning classes with his host. Cot and bedding was provided.
Rewind to duffle bag topic... keep in mind when packing your child for this visit that room is probably at a premium. We sail and have always had space issues when trying to squeeze two adults, two children and one dog onto a sailboat with the assorted "stuff" that is required to keep all those people (and dog) fed, clothed and amused while afloat. Duffle bags are usually a manageable size and pliable enough to fit into tight spaces when room is not abundant. Your host student will probably be forever grateful to the families who pack the visitor's necessitites in a modest size duffle, rather than a big old, rectangular, hard sided wheeled suitcase!
Again, my profound thanks for all the posts giving me feedback in preparing for this visit. Had I not been alerted here, I would not have realized that casual clothes/shoes would be needed for the evening. THANKS EVERYONE!!!!!!