One of the problems with trying to make a day of visiting stuff in D.C. is that nothing is open for very long. The museums are only open from 10-5. However, if you happen to be there on a Thursday, you can get a free pass to go to the Library of Congress from 4:30-8:30 PM. That way you can do that after your day of museums.
Tickets are available on the Library of Congress website about a month before the day you want to go.
The building is gorgeous.
One thing that you can’t do when you visit during the day is go into the main reading room. You can look at it from above.
But as we were wandering around we ended up in a line that we thought was taking us into an exhibit. Instead we did this.
It’s very fast. Our group was in there for maybe 3 minutes and then were ushered out.