Kids Castle

http://www.kidsonthenet.org.uk/castle/

Explore the different parts of a castle! It's a British website, so it must be accurate! 

Interactive Middle Ages

http://www.learner.org/interactives/middleages/

Learn what it was like to live in the middle ages.  Categories for clothing, health, government, and more.

Biography of America

http://www.learner.org/biographyofamerica/

Thanks to the Annenberg Foundation, we have this website chock full of American history, presented as a narrative, with different sections for different periods of history.  Timelines, maps, images, and story. 

United States Senate; Children's Books and Web Sites about the U.S. Government

http://www.senate.gov/reference/bibliography/kids/kids.htm

When researching our government, why not go straight to the source? This site has a list of books and websites to help discover more about our system of government. Look on the left adn you'll see more areas of the site to explore like Senate Organization and you can even read the whole Constitution!