American Heritage Magazine: Good history articles http://www.americanheritage.com
History Net: Great articles on American history! Great for research! http://www.historynet.com
The American Pageant: From the makers of the textbook, "The American Pageant" http://www.college.hmco.com/history/us/index.htm
The History Place: Great cite for American and world history! http://www.historyplace.com