We'll start with the two heavy hitters, and then work our way down from there.

As the text indicates, John Adams was the first President to occupy the White House, but the building was inspected by George and Martha Washington when it was completed. Not many people know that Martha Washington was the nation's first building inspector.

The United States Capitol– probably the most recognizable building in the world. It was constructed to give the citizen legislators a place to gather and work.

I wonder where the citizen legislators gather and work now...