United States Capitol Historical Society
- Promotes the history of the Capitol and Congress and serves as an informational and educational resource. Includes membership information, an education center, history, exhibits and a gift shop.
- http://www.uschs.org/

The United States Capitol
- Official site maintained by the Architect of the Capitol provides historic and current information on the function and architecture of the Capitol, House and Senate buildings, and surrounding grounds.
- http://www.aoc.gov/