The National Air and Space Museum was a. impressive, b. humongous, and c. a ZOO.
My best advice: don't go on a Saturday. Ever.
Oliver was not concerned about the number of people in the building with him. All he cared about were the airplanes! Everywhere he looked, he could see them.
In fact, at one point he INSISTED that I cradle him in my arms so that he could more easily look up and see all of the aircrafts that were hanging from the ceiling without having to strain his little neck. We stood there forever while he took it all in.
I think we'll try it one more time on a weekday in the off season... otherwise, we are definitely looking forward to a trip to the Steven F. Udvar-Hazy center, the companion facility to the Air and Space museum near Dulles Airport (which many have claimed to be infinitely better than the museum on the mall).