ProQuest History Study Center
National Geographic for Kids
Good starting point for online geography work.Fun site with geography games, activities, etc.
Library of Congress
You can explore for a month through the American Memory Collection and the Online Exhibits, and still not see all the cool stuff located here.
Outline Maps
Outline Maps

PCL Map Collection
A collection of outline and base maps for continents, world regions, countries and states.
Smithsonian For Kids
History for Kids
World Facts
Country Studies
Explorers
Lewis and Clark Links
Explorers
Explorers
Lewis and Clark iSpace