Both the National Air and Space Museum (and/or annexes) and the Smithsonian are what I'd consider highly immersive. If you plan on truly doing either of them justice, then set aside one full day for either. Especially the Air and Space Museum. Very much worth your time to be thorough and explore and read the material.
If you expect to take tours of the White House and/or the Capitol Buildings, then expect to schedule at least 2-3 hours for each. It's not so much that the tours themselves take that long. But take into consideration the security procedures.
You could spend a full day JUST visiting the monuments. Especially if you spend some time at the WWII memorial in the center of the mall.
If you expect to take tours of the White House and/or the Capitol Buildings, then expect to schedule at least 2-3 hours for each. It's not so much that the tours themselves take that long. But take into consideration the security procedures.
You could spend a full day JUST visiting the monuments. Especially if you spend some time at the WWII memorial in the center of the mall.