The Political Graveyard 
http://politicalgraveyard.com

General American History
http://historymatters.gmu.edu

American Financial Markets
http://www.financialhistory.org

New-York Historical Society
http://www.nyhistory.org

Who was Hobey Baker?
http://www.hobeybaker.com

Hoop History
http://www.hoophall.com

The Irish
http://www.thewildgeese.com

Naval History
http://www.history.navy.mil

The National Pastime
http://baseballhalloffame.org

Immigrants to America
www.ellisisland.org

The Great War
www.firstworldwar.com

Good TV
http://www.historychannel.com

The Space Age
http://history.nasa.gov

Imperial War Museum, London
http://www.iwm.org.uk

Henry Ford Museum
http://www.hfmgv.org

The Civil War http://www.americancivilwar.info

Victorian Britain http://www.victorianweb.org

Can't Leave This Out
http://www.lawsonbowlingclub.com

Asia 
http://asiasociety.org

The Roman Empire
http://www.roman-empire.net

California
http://www.californiahistoricalsociety.org

Africa
http://www.africabib.org

Who was Fela?
http://www.felaproject.net

Primary Source Documents:  Ancient, Medieval & Modern
http://www.fordham.edu/halsall

Library of Congress:  American Memory
Historical Collections for the National Digital Library
http://memory.loc.gov