George Washington laid the cornerstone of the Capitol Building in Washington DC. It was far from complete by the time that Congress moved in 1800. There are some excellent guides to the history and architecture of the Capitol - my favourite (which I keep by my bedside for a little late night or early morning reading) is William C Allen's "History of the United States Capitol: A chronicle of design, construction, and politics"
It is available in the gift shop in the Capitol Visitors Center, Washington DC - but I wouldn't recommend flying with it (unless you want to use up quite a bit of your baggage allowance!).
Online there is some excellent material on the website of the Architect of the Capitol - available here.