Visiting the U.S. Capitol nowadays is NOTHING like it was even 20 years ago or even 10 years ago.
Tense, high security, unfriendliness everywhere—tourists are shuffled quickly around after waiting for HOURS and being stripped of all their belongings.
In fact, visiting DC in general is much like this now (except, oddly, the U.S. Supreme Court, which has relative light security).
The White House is completely closed to visitors now unless you ask your Senator/Reps 6 mo in advance to run SSN checks (for even your children) and you HAVE to be a party of 10. And even then the request is rarely granted.
So no families are welcomed at all.
That's probably because the "tourists" started dressing like they were going to a backyard barbeque instead of like they were visiting the national shrines.
Today I doubt that anyone even realizes that different standards of dress would apply.
Tell me a about it. Back before 9/11, you were free to walk around the Capitol during regular business hours on self-guided tours. I used to go meet my friend for lunch when he was working for Hastert, and the guards would just ask me where I was going (more to make sure I didn't get lost), then let me go without incident after I went through the metal detectors.
I once ended up getting directions from Spence Abaraham when I took a wrong turn. Nice guy.
Now, even if you're there on official business, you need to get an escort to wherever you're going. And forget about self-guided tours. The Capitol is pretty much closed off, other than official tours, and those are run like the tourists are nuisances, rather than American citizens here to see the heart of our Republic.