Digital Public Library of America: "providing open and coherent access to our society’s digitized cultural heritage"
IPL2: information you can trust
Library of Congress: Country Studies
U.S. Dep't of State: Countries Background Notes
U.S. Government Publishing Office: browse U.S. government publications
WA State HistoryLink: the free online encyclopedia of Washington State history
World History Interactive Atlas and Timeline: jump through the centuries back to 3000 B.C. to see how borders and place names have changed.
What about Wikipedia? Watch this video for wise advice on how Wikipedia can be used.